Answers - The Robert Napier School
Answers - The Robert Napier School
Answers - The Robert Napier School
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<strong>Answers</strong><br />
<strong>Answers</strong><br />
Chapter 1 <strong>Answers</strong><br />
1.1 Get Ready<br />
1 a Neither b Factor c Factor d Multiple<br />
e Neither f Factor<br />
2 a No b Yes c No d Yes e No<br />
Exercise 1A<br />
1 Yes, for example 2 3 5 is prime.<br />
2 4<br />
3 n 2, m 3, p 7<br />
4 a 2, 24 b 5, 10 c 2, 20 d 6, 18<br />
5 a 24 2 3 3, 60 2 2 3 5<br />
b 12 c 120<br />
6 a 72 2 3 3 2 , 120 2 3 3 5<br />
b 24 c 360<br />
7 a 18, 180 b 18, 216 c 12, 480 d 36, 720<br />
8 a 6 b 2520<br />
9 a 40 b 126 000<br />
10 a 11, 13, 17 and 19 are prime numbers between 10 and 20.<br />
b 23, 29, 31 and 37 are prime numbers between 20 and 40.<br />
c 37, 41, 43, 47, 53, 59, 61 and 67 are prime numbers<br />
between 34 and 68.<br />
11 Every 2 minutes<br />
12 3 boxes of burgers and 4 packets of buns<br />
13 No. If one of the prime numbers is 2 you will get an even<br />
number.<br />
1.2 Get Ready<br />
1 a 36 b 8 c 9<br />
Exercise 1B<br />
1 a 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225<br />
b 1, 8, 27, 64, 125<br />
2 a i 64, 1, 49, 9 ii 64, 1, 8<br />
b i 4, 16 ii 125, 27<br />
c i 64, 81, 144 ii 125, 64<br />
d i 100, 81, 169, 64 ii 125, 64<br />
Exercise 1C<br />
1 a 9 b 49 c 64<br />
d 1000 e 121<br />
2 a 6 b 4 c 9<br />
d 1 e 8<br />
3 a 36 b 8 c 81<br />
d 1 e 144<br />
4 a 2 b 3 c 1<br />
d 4 e 10<br />
5 a 17 b 50 c 250<br />
d 14 e 1 f 8<br />
g 34 h 11 i 9<br />
j 50 k 10 l 6<br />
1.3 Get Ready<br />
1 a 18 b 16 c 10<br />
Exercise 1D<br />
1 a 25 b 13 c 6 d 4<br />
e 5 f 8 g 6 h 2<br />
i 1 j 5 k 14 l 52<br />
m 32 n 15 o 8 p 70<br />
2 a 49 b 25 c 243 d 123<br />
e 72 f 69 g 7 h 7<br />
3 a 25 b 4 c 8 d 31<br />
1.4 Get Ready<br />
a 20 000 b 100 c 49<br />
Exercise 1E<br />
1 a 31 b 6.4 c 17 d 1.5<br />
e 32<br />
2 a 39.36 b 32.65 c 5.76 d 155.125<br />
3 a 219.5 b 305.7 c 22.6 d 410.9<br />
4 a 5.17 b 5.34 c 3.16 d 1.67<br />
5 a 2.77 b 7.68 c 205 d 455 000<br />
6 a 0.917 b 1.08 c 8.67 d 15.8<br />
Exercise 1F<br />
1 a 0.25 b 1.6 c 0.156 25 d 2 3 8<br />
1.5 Get Ready<br />
1 32<br />
2 125<br />
3 729<br />
Exercise 1G<br />
1 a 6 12 b 4 5 c 7 6<br />
d 5 6 e 3 10<br />
2 a 100 000 b 125 c 64<br />
d 9 e 64<br />
3 a 5 b 3 c 5<br />
d 4 e 9<br />
4 a 3 4 b 5 9 c 2 6<br />
d 6 5 e 4 2<br />
5 a 9 b 16 c 16<br />
d 10 000 e 49<br />
6 a 3 b 5 c 2<br />
d 4 e 3<br />
Review exercise<br />
1 a 96 b 33 c 23<br />
2 a 4 b 4 c 2 d 4<br />
e 2<br />
3 a 2 b 2 c 16<br />
637<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 637<br />
05/09/12 5:15 PM
<strong>Answers</strong><br />
4 a 100 cans b 14 (with 4 cans spare)<br />
c 200 cans d 14 (with 8 cans spare)<br />
5 a 5 arrangements: 1 by 36, 2 by 18, 3 by 12, 4 by 9, 6 by 6<br />
b 3 arrangements: 1 by 18, 2 by 9, 3 by 6<br />
c 3 arrangements: 1 by 12, 2 by 6, 3 by 4<br />
6 64 is the next number which is both a square number and<br />
a cube number.<br />
7 a 5 760 000 b 5 760 000 c 160<br />
d 57 600 e 2304<br />
8 a 3 b 30 c 0<br />
9 a 3 2 b 4 c 2 12 d 5 2<br />
10 a 2 2 3 2 7<br />
b 2 3 3 3 7<br />
11 9, 15<br />
12 84 2 2 3 7<br />
168 2 2 6 3 2 7 2<br />
13 120 000 miles<br />
14 1.258 048 316<br />
15 3<br />
16 a False, e.g. 3 5 8<br />
b False, e.g. 4 9 13<br />
c False, e.g. 5 3 2<br />
d False, e.g. 2 3 6<br />
e True<br />
17 a 2 7 128 b 2020<br />
Chapter 2 <strong>Answers</strong><br />
2.1 Get Ready<br />
1 4a 2 8c 3 2p 2<br />
Exercise 2A<br />
1 a 7x 4y b 10w 2z c 4p 5q<br />
d 3a b e 6c 2d f 2m 3n<br />
g 4e 7f h 2x 10y 2 i 2p 3q 5<br />
j 13 5b 4a<br />
2 5x 9<br />
3 5x 13y<br />
2.2 Get Ready<br />
1 4x 2y 12 2 6y 2x 4 3 8x 2y 6<br />
Exercise 2B<br />
1 a 1 b 5 c 16 d 15<br />
2 a 4 b 19 c 5 d 11<br />
e 17 f 11<br />
2.3 Get Ready<br />
1 4 11 2 7 7 3 6 6<br />
Exercise 2C<br />
1 a m 5 b 6p 2 c 20q 3<br />
2 a a 11 b n 4 c x 6 d y 9<br />
3 a 12p 6 b 12a 5 c 5b 9 d 18n 3<br />
4 a 20t 8 u 5 b 6x 6 y 7 c 7a 5 b 6 d 8c 2 d 9<br />
e 24m 6 n 5<br />
Exercise 2D<br />
1 a a 3 b b 4 c c 3 d d<br />
2 a 2q 2 b 3p 5 c 4x d 10y 7<br />
3 a 5a 2 b 4 b 5pq 3 c 4c 2 d 4 d 3x 5<br />
e 10m 2 n<br />
Exercise 2E<br />
1 a a 14 b b 15 c c 9 d d 16<br />
2 a 4p 6 b 81q 8 c 25x 8 d<br />
3 a 16x 12 y 8 b 49e 10 f 6 c 125p 15 q 3 d<br />
2.4 Get Ready<br />
1 a 18 2 27y 15 3 ___ 4a2<br />
b 6<br />
Exercise 2F<br />
12 m__<br />
8<br />
____ 8x 9<br />
27y 6<br />
1 a<br />
1__ b<br />
1__<br />
a<br />
b 2 c __ 1<br />
c 2 d ___ 1<br />
d 3<br />
2 a<br />
1__<br />
e 6 b __ 1<br />
f 8 c x2 d y<br />
3 a 1 b 1 c _____ 1<br />
5p 2 q 4<br />
d ______ 1<br />
27c 9 d 3 e _____ 9r 4<br />
4p 6 q 2<br />
Exercise 2G<br />
1 a 3a 2 b 2c 1_<br />
2<br />
c<br />
2 a<br />
__ 1<br />
a 2 b __ 1<br />
2c<br />
2.5 Get Ready<br />
c<br />
3_<br />
___ 3e<br />
3<br />
d 10x<br />
f<br />
____ 1<br />
d ____ 1<br />
2x 9_<br />
5<br />
y x 1_<br />
2<br />
y 3_<br />
2<br />
1 12, 14, 16 2 34, 39, 44, 3 11, 13, 15<br />
Exercise 2H<br />
1 a add 3 b 14, 17 c 29<br />
2 a add 6 b 20, 26 c 50<br />
3 a subtract 7 b 9, 16 c 44<br />
4 a add 1 to the difference of consecutive terms<br />
b 15, 21 c 55<br />
5 a add 2 to the difference of consecutive terms<br />
b 20, 30 c 90<br />
2.6 Get Ready<br />
1 a add 3 b 13, 16 c 28<br />
2 a add 3 b 11, 14 c 23<br />
3 a subtract 6 b 94, 88 c 70<br />
Exercise 2I<br />
2<br />
y 5_<br />
2<br />
1 a i 2 ii 2<br />
b i 4<br />
ii 11<br />
c i 5 ii 19<br />
2 a 6n 5 b i 67 ii 295<br />
3 a 4n 3 b i 63 ii 403<br />
4 a 37 5n b i 63 ii 963<br />
5 7n 11 103 has no integer solution<br />
6 a 4n 3 b 4n 3 453 has no integer solution<br />
638<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 638<br />
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<strong>Answers</strong><br />
Review exercise<br />
1 a 5x 5y b 6m 10n<br />
2 a 240B 114A, B British stamp, A Australian stamp<br />
b 375B 212A<br />
3 a 3 b 8 c 7 d 30 e 62<br />
4 a y 3 b 3x 2 c z 8 d p 7 e 16a 7<br />
5 a a 3 b b 5 c 7p 3 d 8x 3 e 8a<br />
6 a subtract 3 b 87, 84 c 69<br />
7 a 5 b 8<br />
8 a 216 12n b i 60 ii 972<br />
9 <strong>The</strong> nth term in the sequence is 3n 2. If 3n 2 140,<br />
n 46. So 140 is the 46th term in the sequence.<br />
10 a 55 cans<br />
b Students’ proofs<br />
c 19 high (with 10 cans spare)<br />
11 a 5 1_ hours b 3.03 hours 3 hours 2 mins<br />
2<br />
c Naismith’s formula is for fit experienced walkers.<br />
12 a a 20 b 9b 8 c 27e 15 f 3<br />
13 Three consecutive even numbers are 2n, 2n 2, 2n 4.<br />
<strong>The</strong>ir sum 2n 2n 2 2n 4 6n 6, which is<br />
always a multiple of 6.<br />
14 ____ 6x 2 y<br />
4y 3 ___ 3x2<br />
2<br />
. Squared numbers cannot be negative.<br />
2y<br />
15 a<br />
3p 2 ___<br />
2y<br />
b<br />
1 ___<br />
4q 6<br />
16 64 cubes 8 have 0 sides painted<br />
24 have 1 side painted<br />
24 have 2 sides painted<br />
8 have 3 sides painted<br />
c<br />
2y ___<br />
x 2<br />
Sides of cube 0 1 2 3<br />
n by n by n (n 2) 3 6(n 2) 2 12(n 2) 8<br />
Chapter 3 <strong>Answers</strong><br />
3.1 Get Ready<br />
1 8_ 9 2 __ 19<br />
8 3 9 2_<br />
5<br />
Exercise 3A<br />
8<br />
1 a __<br />
11 b 5_<br />
9 c __ 11<br />
15 d 2_<br />
5<br />
7<br />
2 a __<br />
10 b __ 10<br />
21 c __ 29<br />
35 d 8_<br />
9<br />
13<br />
e __<br />
20 f __ 13<br />
18 g __ 7<br />
18 h 3_<br />
4<br />
3 a<br />
1_<br />
4 b __ 1<br />
12 c __ 19<br />
40 d 2_<br />
9<br />
e<br />
1_<br />
4 f __ 5<br />
12 g __ 1<br />
10 h __ 1<br />
18<br />
4 a 1 11<br />
40 b 1 __ 11<br />
20 c 1_<br />
6 d __ 19<br />
20<br />
e 1 11<br />
15 f 1 5_<br />
8 g 1 1_<br />
5 h 1 __ 5<br />
18<br />
Exercise 3B<br />
1 a 8 1_<br />
4 b 5 __ 3<br />
10 c 11 __ 5<br />
42 d 18 __ 3<br />
20<br />
2 7 1 miles<br />
22<br />
3 1 12<br />
35 lb<br />
Exercise 3C<br />
1 a 1 1_<br />
4 b 2 3_<br />
8 c 3_<br />
4 d 3 1_<br />
3<br />
2 a<br />
3_<br />
4 b 1 __ 7<br />
12 c 2 __ 24<br />
35 d 3 4_<br />
9<br />
3 3 3_<br />
8 kg<br />
4 2 7_<br />
8 pints<br />
3.2 Get Ready<br />
1 32 2 45 3 __ 19<br />
5 4 4 2_<br />
3<br />
Exercise 3D<br />
1 a<br />
__ 3<br />
10 b __ 3<br />
20 c __ 6<br />
11 d 2_<br />
9<br />
__ 4<br />
__<br />
__<br />
__<br />
e<br />
2 a<br />
2_<br />
3 b 3_<br />
4 c 3 3_<br />
5 d 15<br />
3 a 21 kg b 6 2_<br />
3 m c 7 1_<br />
1_<br />
litres d 7<br />
2 2 pints<br />
4 21<br />
5 £32.65<br />
5<br />
6 a __<br />
12 b 4_<br />
5 c 4 1_<br />
8 d 7<br />
21 f 9<br />
20 g 3<br />
10 h 15<br />
32<br />
e 3 f 4 3_<br />
8<br />
7 14 5_<br />
8 minutes<br />
8 20 5_<br />
8 lb<br />
3.3 Get Ready<br />
1<br />
__ 6<br />
35 2 1_ 6 3 __ 24<br />
7<br />
Exercise 3E<br />
g 10 h 22<br />
1_<br />
2<br />
5<br />
1 a __<br />
12 b __ 3<br />
16 c 2 2_<br />
3 d 1 1_<br />
2<br />
e<br />
3_<br />
4 f 1 1_<br />
5 g 1 __ 11<br />
14 h 5_<br />
6<br />
2 a<br />
1_<br />
2 b 28 c 2 __ 1<br />
12 d 2 __ 4<br />
13<br />
e 2 f 3 2_<br />
3 g 6 h 1 7_<br />
8<br />
3 16<br />
4 36<br />
5 11 __ 2<br />
11 days<br />
3.4 Get Ready<br />
1 7_ 8 2 __ 4<br />
45 3 3 5_<br />
8<br />
Exercise 3F<br />
1 a<br />
5_<br />
6 b 1_<br />
6<br />
2 880 m 3<br />
3 £5.60<br />
4 £78<br />
5 525<br />
6<br />
3_<br />
1_<br />
36 13 which is not a whole number<br />
8 2<br />
7 4 __ 1<br />
12 hours<br />
8<br />
1_<br />
2<br />
7_<br />
8 km<br />
9<br />
10 192<br />
11 £8.40<br />
Review exercise<br />
1 a<br />
2 a<br />
2_<br />
3 b 4_<br />
5 c 2_<br />
3 d 2_<br />
3 e __ 4<br />
11<br />
__ 17<br />
5 b 5 1_<br />
6<br />
639<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 639<br />
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<strong>Answers</strong><br />
3<br />
Name<br />
Hourly rate<br />
Hourly rate at<br />
time and a half<br />
Aaron £8.50 £12.75 £17.00<br />
Chi £12.00 £18.00 £24.00<br />
Mahmood £14.40 £21.60 £28.80<br />
__ 13<br />
Hourly rate at<br />
double time<br />
4 a<br />
20 b 1 __ 7<br />
12 c 5 __ 7<br />
12<br />
5 a £374 b 6 hours<br />
1<br />
6 a __<br />
12 b 3 __ 13<br />
30 c 1 __ 11<br />
12<br />
7 a 4 1_<br />
6 m2 b 8 1_<br />
3 m c 5_<br />
6 m<br />
8 Yes, the part is 6 2 cm long.<br />
16<br />
9 720 000 m 2<br />
10 3 1<br />
12 miles<br />
11 a 8 7 inches<br />
16<br />
1_<br />
b 114 12 a 8<br />
15 , b 1_<br />
3 , c 1_<br />
5 , d 4<br />
15<br />
13 64<br />
14 350<br />
15 a<br />
1_<br />
4 b 1_<br />
8 c 1_<br />
4 d 3_<br />
8<br />
Chapter 4 <strong>Answers</strong><br />
4.1 Get Ready<br />
1 8.02, 8.09, 8.092, 8.2, 8.29, 8.9, 8.92<br />
2 a<br />
1_<br />
3 b __ 7<br />
12 c 7_<br />
8<br />
Exercise 4A<br />
13<br />
d 84 __<br />
24<br />
1 0.8, 0.85, ___ 86<br />
100 , __ 9<br />
10 , 0.98<br />
2 a terminating b terminating c recurring<br />
d recurring e terminating f recurring<br />
3 Mitch is correct, as there is a factor of 3 in the denominator.<br />
4.2 Get Ready<br />
1 a 18.79 b 5.18 c 32.74<br />
Exercise 4B<br />
1 a 0.12 b 0.0012 c 0.04 d 0.0063<br />
2 a 2.536 b 1.263 c 0.043 38 d 2.52<br />
e 13.02 f 0.504 g 0.046 72 h 0.323<br />
3 15p<br />
4 £6.86<br />
5 a 60 b 14 c 640 d 65<br />
e 25 f 2040 g 0.05 h 0.092<br />
6 a 231 b 642 c 41.3 d 42.2<br />
7 £26.13<br />
8 5<br />
4.3 Get Ready<br />
1 a 0.5772 b 160.3 . c £1.41<br />
Exercise 4C<br />
1 a 6.4 b 5.7 c 16.9<br />
d 0.1 e 1.0<br />
2 a 5.67 b 8.06 c 0.13<br />
d 3.04 e 0.08<br />
3 a 6.446 b 0.079 c 5.079<br />
d 6.008 e 0.020<br />
4.4 Get Ready<br />
1 a 3 b 0 c 9<br />
2 e.g. 438, 48, 6798<br />
Exercise 4D<br />
1 a 3900 b 230 c 46<br />
d 6.5 e 5.1 f 0.43<br />
2 a 2500 b 39.0 c 4.90<br />
d 4.09 e 0.0110<br />
3 a 3000 b 40 c 3<br />
d 8 e 20 f 1<br />
4.5 Get Ready<br />
1 a 5000 b 20 c 7<br />
2 a 600 b 15 000 c 540 000<br />
3 a 60 b 300 c 0.025<br />
Exercise 4E<br />
1 a 4200 b 7000 c 6000<br />
d 200 000 e 80 000<br />
2 a 35 b 2 c 10 d 5 e 6<br />
3 a 8000, overestimate b 4, overestimate<br />
c 10, underestimate d 300, overestimate<br />
4 a 50, overestimate b 4, underestimate<br />
c 40, overestimate d 8, overestimate<br />
5 2400<br />
4.6 Get Ready<br />
1 a 0.3 b 0.05 c 0.001<br />
2 a 6 b 150 c 0.054<br />
3 a 6000 b 30 000 c 25<br />
Exercise 4F<br />
1 a 2.4 b 0.15 c 1 d 0.0018<br />
2 a 20 b 50 c 100 d 4<br />
e 0.2<br />
3 a 1.5, underestimate b 0.2, overestimate<br />
c 5, underestimate d 200, underestimate<br />
4 a 400, overestimate b 210, overestimate<br />
c 25, underestimate d 4000, underestimate<br />
5 0.25<br />
4.7 Get Ready<br />
1 a 60 b 600 c 6000<br />
2 a 30 b 3 c 0.3<br />
Exercise 4G<br />
1 a 1792 b 1792 c 17.92 d 0.017 92<br />
2 a 146.4 b 1.464 c 0.1464 d 0.014 64<br />
3 a 348 b 3480 c 34.8 d 348<br />
640<br />
CS4-Z01_EMHA_SB_GCSE_0839_ANS.indd 640<br />
8/18/12 12:54 PM
<strong>Answers</strong><br />
4 a 128.8 b 230 c 56 d 2<br />
5 a 0.026 b 340 c 0.034 d 100<br />
6 a 13 b 13 c 13 000 d 0.065<br />
4.8 Get Ready<br />
1 a terminating b recurring c recurring<br />
Exercise 4H<br />
1<br />
7_<br />
9 2 __ 34<br />
2<br />
4 __<br />
11 5 ___ 317<br />
323<br />
7 ___<br />
990 8 ___ 347<br />
10 6 83<br />
99 11 2 __ 7<br />
66<br />
99 3 ___ 305<br />
333<br />
999 6 __ 1<br />
18<br />
495 9 __ 7<br />
30<br />
317<br />
12 7 900<br />
4.9 Get Ready<br />
1 a 6.1 b 7.0 c 6.5 d 6.5<br />
2 a 0.3 b 0.3 c 0.3 d 0.3<br />
Exercise 4I<br />
1 a 84.5, 83.5 b 84.05, 83.95 c 84.005, 83.995<br />
2 a 0.95, 0.85 b 0.905, 0.895 c 0.095, 0.085<br />
3 a 118.5 cm b 117.5 cm<br />
4 a 6450 g b 6350 g<br />
5 a 48.05 l b 47.95 l<br />
6 a 1.005 m b 0.995 m<br />
4.10 Get Ready<br />
1 10.1<br />
2 2.1<br />
3 a e and f b c and f c e and f d c and f<br />
Exercise 4J<br />
1 a 535 b 26 612.25 c 229 920.25<br />
2 a 6.88 b 10.823 575 c 24.35<br />
3 a 11 275 568.625 b 151 474.75<br />
4 a 11 b 1.3606…<br />
5 a 0.8 b 1.3137…<br />
6 a 31.3375 b 29.8275 c 30 (1 s.f.)<br />
7 2.05 10 17 (3 s.f.), 2.28 10 17 (3 s.f.)<br />
8 a 50 b 15.5%<br />
Review exercise<br />
1 £153.90<br />
2<br />
2_<br />
3<br />
3 0.47, 12<br />
25 , 3_<br />
5 , 31<br />
50<br />
4 £42.96<br />
5 a 4780 b 107 c 3.23 10 15<br />
d 7000 e 57.0<br />
6 a 46 b 31 c 0.046<br />
d 20 e 4.1<br />
7 a 400 b 40 c 1 10 18<br />
d 0.005 e 3<br />
8 a 3.1 b 0.6 c 2.1 d 4.0<br />
77<br />
9 a ___<br />
400 b __ 77 1_<br />
19<br />
4 4 c _____ 770 000<br />
192 500<br />
4<br />
10 76 923 1p pieces<br />
11 a Students’ checks<br />
b<br />
A B C Best deal<br />
John £56.74 £62.27 £64.33 Avery Energy<br />
Vijay £192.37 £186.17 £280.42 Brawn Power<br />
12 a 3000 b 4000 c 24<br />
d 350 000 e 360<br />
13 a 5 b 5 c 80<br />
d 250 e 1<br />
14 37 minutes<br />
15 a<br />
3_<br />
1 £3 b __ 30<br />
1.5 £20 c ___ 1500<br />
150 £10<br />
10<br />
d __<br />
2.5 £4 e ___ 300<br />
50 £6 f ___ 2000<br />
10 £200<br />
16 a £21 b 32<br />
17 a 75, underestimate b 150, underestimate<br />
c 3.6, overestimate d 6000, overestimate<br />
e 45 000, overestimate<br />
18 Volume 3 8 9 216 m 3 .<br />
Number of people 216<br />
4 54<br />
19 £429.56<br />
20<br />
1_<br />
3<br />
21 a 17.1 b 31.95 c 60.1425 d 24.5025<br />
22 a 200 b 645 c 1.8163… d 0.0638…<br />
23 lower bound for length is 199.5 cm, so rod may fit into slot<br />
of length 199.8 cm<br />
24 8.75 km/l<br />
25 LB of cylinder’s capacity 325 ml, so the cylinder always<br />
contains more than stated on the label.<br />
Chapter 5 <strong>Answers</strong><br />
5.1 Get Ready<br />
1 a 135°, b 45°, c 135° 2 40° 3 48°<br />
Exercise 5A<br />
1 a 63° (corresponding angles)<br />
b 49° (corresponding angles)<br />
c 68° (angles in a triangle add up to 180°)<br />
2 p 113° (corresponding angles and angles on a straight line)<br />
q 67° (corresponding angles)<br />
r 113° (alternate angles or angles on a straight line)<br />
3 l 81° (vertically opposite angles)<br />
m 54° (alternate angles)<br />
n 45° (angles of a triangle add up to 180°)<br />
4 y 58° (alternate angles)<br />
z 58° (alternate angles and angles on a straight line)<br />
5 g 57° (isosceles triangle and alternate angles)<br />
h 180 2 57 66° (angles of a triangle add up to 180°<br />
and alternate angles)<br />
k 114° (angles of a triangle add up to 180° and angles on<br />
a straight line)<br />
6 a 50° ( 2 sets of alternate angles)<br />
7 a a and p, b and q, c and s, d and r<br />
b a and r, b and s, c and q, d and p<br />
c a and b, b and d, d and c, c and a, p and q, q and r,<br />
r and s, s and p, a and q, a and s, b and p, b and r,<br />
c and p, c and r, d and q, d and s<br />
<strong>The</strong> angles are on a straight line, or correspond to<br />
angles on a straight line.<br />
8 Angle BAC Angle DCE 56°, so they are corresponding<br />
angles<br />
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<strong>Answers</strong><br />
5.2 Get Ready<br />
1 a 50°, b 80° 2 c 29°, d 29°<br />
3 e 60°<br />
Exercise 5B<br />
1 angles in a triangle, angles on a straight line<br />
2 same angle, same angle, angles in a triangle, angles in a<br />
triangle<br />
3 a b d (alternate angles)<br />
a c (corresponding angles)<br />
so a b c d<br />
b <strong>The</strong> exterior angle is equal to the sum of the opposite<br />
two interior angles.<br />
5.3 Get Ready<br />
j 143°<br />
Exercise 5C<br />
1 141° (angle sum of quadrilateral / equilateral triangle)<br />
2 126° (angles on a straight line / exterior angle of a triangle)<br />
3 a a 132° (symmetry), b 37° (angle sum of<br />
quadrilateral)<br />
b 66°, 114°, 114° (symmetry / angle sum of quadrilateral)<br />
4 113° (vertically opposite angles / angles on a straight line /<br />
angles at a point / angle sum of a quadrilateral)<br />
5.4 Get Ready<br />
a alternate angles b 90°<br />
Exercise 5D<br />
1 alternate angles<br />
2<br />
A<br />
30°<br />
5.5 Get Ready<br />
1 a East b South c North-west<br />
Exercise 5E<br />
30°<br />
1 a 073° b 225° c 243°<br />
2 a 070° b 218° c 102°<br />
3 249°<br />
4 312°<br />
5 a 111° b 239°<br />
5.6 Get Ready<br />
a 43° (alternate angles)<br />
b 72° (opposite angles)<br />
c 65° (angles sum of a triangle)<br />
d 64° (angles on a straight line)<br />
e 58° (angle sum of an isosceles triangle)<br />
f 54° (opposite angles of a parallelogram)<br />
g 126° (angles at the end of a parallelogram)<br />
Exercise 5F<br />
1 a 124° (isosceles triangle / angle sum of a triangle /<br />
vertically opposite angles)<br />
b 56° (angles on a straight line / corresponding angles)<br />
2 L 70°, M 55°, N 55° (alternate angles / angles on a<br />
straight line)<br />
3 a p 57° (exterior angle of a triangle / angle sum of a<br />
quadrilateral)<br />
b q 117° (exterior angle of a triangle / corresponding<br />
angles)<br />
4 a alternate angles<br />
b b d (alternate angles)<br />
a c, part a<br />
so a b c d<br />
c Opposite angles in a parallelogram are equal.<br />
5 a b c d 360° (angles in a quadrilateral)<br />
a c 180° (given in question)<br />
so b d 180°<br />
5.7 Get Ready<br />
1 Equilateral triangle<br />
2 A square is a quadrilateral with equal sides and equal<br />
angles.<br />
Exercise 5G<br />
1 a<br />
Polygon<br />
Number<br />
of sides<br />
(n)<br />
Number of<br />
diagonals<br />
from one<br />
vertex<br />
Number<br />
of<br />
triangles<br />
formed<br />
Sum of<br />
interior<br />
angles<br />
Triangle 3 0 1 180°<br />
Quadrilateral 4 1 2 360°<br />
Pentagon 5 2 3 540°<br />
Hexagon 6 3 4 720°<br />
Heptagon 7 4 5 900°<br />
Octagon 8 5 6 1080°<br />
Nonagon 9 6 7 1260°<br />
Decagon 10 7 8 1440°<br />
b i n 3 ii n 2 iii (n 2) 180°<br />
2 Angles not equal<br />
Exercise 5H<br />
1 a 15 b 18 c 160°<br />
2 a 120° b 144° c 168°<br />
3 a 142° b 103°<br />
4 360 is not divisible by 25<br />
5 a a 32°, b 30°, c 42°, d 63°, e 44°, f 27°,<br />
g 59°, h 63°<br />
b 360°<br />
6 a 135° (angle sum of isosceles triangle / angles on a<br />
straight line)<br />
b i <strong>The</strong> interior angles are all the same.<br />
ii Not all the sides are the same length.<br />
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<strong>Answers</strong><br />
Exercise 5I<br />
1 a i 110° ii 143°<br />
b i 50° ii 36°<br />
2 a 72° b 45° c 30° d 14.4°<br />
3 a 24 b 3960°<br />
4 144°, 98°, 129°, 128°, 107° and 114°<br />
5 Exterior angle 12°, interior angle 168°, angle BCA 6°<br />
(angle sum of isosceles triangle)<br />
6 Angle BCD 180 e (angles on a straight line)<br />
So angle BCO (180 e) 2 (by symmetry)<br />
And angle CBO (180 e) 2 (isosceles triangle)<br />
So c 180 {(180 e) 2} {(180 e) 2} (angles in<br />
a triangle) giving c e<br />
Review exercise<br />
1 88 96 180, so the lines are not parallel. Ben is right.<br />
2 Angles on a straight line add up to 180°,<br />
but 120 50 180.<br />
3 a x 30°<br />
b vertically opposite angles<br />
c Angles around a point add up to 360°,<br />
but 125 135 125 360.<br />
4 a i x ________ 180 54<br />
63°<br />
2<br />
ii angle sum of an isosceles triangle<br />
b y 54 63 117° (exterior angle of a triangle)<br />
or<br />
y 180 63 117° (angles on a straight line)<br />
5<br />
N<br />
N<br />
50°<br />
60°<br />
Q<br />
P<br />
6 a y 58°<br />
b alternate angles<br />
7 x 130° (angles on a straight line)<br />
y 50° (alternate angles)<br />
8 x 180 (360 50 119 105) 94° (angle sum of a<br />
quadrilateral / angles on a straight line)<br />
9 a x 180 2 52 76°<br />
b angle sum of an isosceles triangle<br />
10 angle ABQ 90° (angle in a square)<br />
angle ABC 180 ___ 360 120° (exterior angle of a regular<br />
6<br />
polygon / angles on a straight line)<br />
x 360 90 120 150° (angles around a point)<br />
11 a angle BDA 180 127 53° (angles on a straight<br />
line)<br />
angle BAD 180 2 53 74° (angle sum of an<br />
isosceles triangle)<br />
angle DAC 90 74 16°<br />
b angle DCA 180 127 16 37° (angle sum of a<br />
triangle)<br />
12 angle in equilateral triangle 60°<br />
base angle in isosceles triangle ________ 180 57<br />
61.5°<br />
2<br />
(angle sum of a triangle)<br />
p 360 60 61.5 238.5° (angles around a point)<br />
13 a i w 25° (base angles of an isosceles triangle)<br />
ii x 180 2 25 130° (angle sum of a triangle)<br />
b angle SQR 180 130 50° (angles on a straight<br />
line)<br />
y ________ 180 50<br />
65° (angle sum of an isosceles<br />
2<br />
triangle)<br />
14 a 030°<br />
b N B<br />
A<br />
135°<br />
15 exterior angle ___ 360<br />
10 36°<br />
x 180 36 144° (angles on a straight line)<br />
16 a x _________ 180 120<br />
30° (angle sum of an isosceles<br />
2<br />
triangle)<br />
b angle ABD 180 30 150° (angles on a straight<br />
line)<br />
y 360 150 54 108 48° (angle sum of a<br />
quadrilateral)<br />
17 angle ACB angle ABC x 20 (base angles of an<br />
isosceles triangle)<br />
angle BAC 2(x 20) 180° (angle sum of a triangle)<br />
angle BAC 140 2x<br />
18 angle EFD 360 2x 65 x 90 205 3x<br />
(angles around a point)<br />
angle FED angle EFD 205 3x<br />
(base angles of an isosceles triangle)<br />
19 a interior angle 180 exterior angle<br />
(angles on a straight line)<br />
interior angle 180 2_ interior angle<br />
3<br />
interior angle 108°<br />
b exterior angle 72° ___ 360<br />
n<br />
n 5<br />
20 Angle CAB 360 x 90 80 x<br />
(Angles at a point add up to 360°)<br />
190 2x angle ABC<br />
(Base angles in an isosceles triangle are equal)<br />
Angle BCD 190 2x 190 2x<br />
(exterior angle of a triangle sum of two interior opposite<br />
angles)<br />
380 4x 4(95° x)<br />
21 Angle PQR angle PRQ (180° 20°) 2 80°<br />
(base angles of an isosceles triangle are equal and Angles<br />
in a triangle add up to 180°)<br />
Angle PQY 80° 60° 20°<br />
Since angle PQY 20° and angle QPY 20°, triangle PQY<br />
is isosceles.<br />
Thus PY QY<br />
(sides opposite the equal angles in an isosceles triangle<br />
are equal)<br />
22 5 minutes and 27 seconds past 1<br />
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<strong>Answers</strong><br />
Chapter 6 <strong>Answers</strong><br />
6.1 Get Ready<br />
a Ask each classmate how much lunch money they get and<br />
calculate the mean of this data.<br />
b Use an internet air ticketing site or the Manchester airport<br />
site.<br />
c Search the internet for a government site that gives<br />
information on voting figures.<br />
Exercise 6A<br />
1 a secondary b secondary c primary<br />
2 a quantitative b qualitative c quantitative<br />
d quantitative<br />
3 a discrete b continuous c continuous<br />
d discrete<br />
4 a Drug A is effective at curing malaria OR Drug A is not<br />
effective at curing malaria.<br />
b Collect data on patients that have been treated with<br />
Drug A and those that haven’t.<br />
6.2 Get Ready<br />
If the answers are written down: 15 seconds<br />
If the answers are given orally (i.e. one student at a time):<br />
number of students in class 15 seconds.<br />
Exercise 6B<br />
1 For example, rolling a dice or using the random function on<br />
a calculator or from a random number table<br />
2 A fraction of the population is chosen at random.<br />
3 For example, assign the numbers 1 to 60 to the workers,<br />
then take the first eight different numbers under 61 that are<br />
generated by the calculator<br />
(21, 32, 54, 34, 26, 45, 35, 22)<br />
6.3 Get Ready<br />
15<br />
1 a __<br />
25 3_<br />
2 a 80 b<br />
5 b __ 10<br />
25 2_<br />
5<br />
3_<br />
8<br />
Exercise 6C<br />
1 23 boys, 27 girls<br />
2 Randomly select 15 employees with less than six months’<br />
experience and 40 employees with more than six months’<br />
experience.<br />
3<br />
Office Factory floor Managers<br />
workers workers<br />
Females 5 25 1<br />
Males 8 49 2<br />
<strong>The</strong>y should be picked by simple random sampling.<br />
6.4 Get Ready<br />
1 a 4 b 6<br />
2<br />
Exercise 6D<br />
1 a Vehicle Frequency<br />
Car<br />
Bus<br />
HGV<br />
Bike<br />
Motorbike<br />
b Motorbike<br />
c Car<br />
2 Number of DVDs bought Frequency<br />
0–3 9<br />
4–7 11<br />
8–11 6<br />
12–15 4<br />
3 a Weight Frequency<br />
57 w 60 7<br />
60 w 63 3<br />
63 w 66 5<br />
66 w 69 5<br />
w 69 4<br />
b 57 w 60 c 60 w 63<br />
6.5 Get Ready<br />
Tallying<br />
Exercise 6E<br />
1 It is a biased question.<br />
2 A: open, B: closed, C: open, D: closed<br />
3 a No option for dissatisfied customers.<br />
New suitable question:<br />
What do you think of the new amusements?<br />
Very good Good Satisfactory Poor<br />
b Options overlap.<br />
New suitable question:<br />
How much money would you normally expect to pay for<br />
each amusement?<br />
£5–£7 £7.01–£8 more than £8<br />
c Not clear what the options mean.<br />
New suitable question:<br />
How often do you visit the park each year?<br />
0–2 times 3–5 times 6–8 times<br />
more than 8 times<br />
4 Do you like the new layout? Yes/No<br />
6.6 Get Ready<br />
1 a 15 girls b 6 students<br />
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<strong>Answers</strong><br />
Exercise 6F<br />
1 a Plain Salt and Cheese and Total<br />
Vinegar Onion<br />
Males 7 7 14 28<br />
Females 5 6 12 23<br />
Total 12 13 26 51<br />
b 13 c 51<br />
2 a Orange<br />
Juice<br />
Grapefruit<br />
Juice<br />
Total<br />
Men 22 8 30<br />
Women 18 12 30<br />
Total 40 20 60<br />
b 40<br />
3 a Supervisors Office Shop floor Total<br />
staff workers<br />
Males 10 3 82 95<br />
Females 2 11 38 51<br />
Total 12 14 120 146<br />
b 51 c 146<br />
Exercise 6G<br />
1 Yes, only one area sampled<br />
2 A: Biased. Not everyone in the hospital’s area has a chance<br />
of being asked.<br />
B: Biased. Only people with phones have a chance of being<br />
asked and only in 10 towns, the sample is too small.<br />
C: Not biased.<br />
D: Biased. Only people already using the recycling facility<br />
are being asked.<br />
3 Students' own discussions<br />
6.8 Get Ready<br />
<strong>The</strong> internet, supermarkets, high street shops<br />
Exercise 6H<br />
1 a 41 000 tonnes b Cars c 2004<br />
d Cars<br />
2 a 6.3 days b May c May d May<br />
3 a 799 b Stays the same<br />
c More dairy d Numbers have decreased<br />
Review exercise<br />
1 a It does not allow for sending no text messages. It does<br />
not include a time frame, e.g. per week.<br />
b It only includes people of one age.<br />
2 a <strong>The</strong> categories overlap. It does not include a time frame,<br />
e.g. per day. It does not allow for people who use their<br />
computer for more than 6 hours.<br />
b It only includes people of one age.<br />
3 a It does not allow for never visiting the cinema. It is hard<br />
to decide what the categories mean. It does not include<br />
a time frame, e.g. per month.<br />
b On average, how many times do you go to the<br />
cinema each month?<br />
0–1 times 2–3 times 4–5 times<br />
more than 5 times<br />
4 On average, how many emails do you send each week?<br />
0–5 6–10 11–15 16–20<br />
more than 20<br />
5 It only includes women. It does not include people who<br />
never go to the cinema.<br />
6<br />
Animal Tally Frequency<br />
7<br />
Lions<br />
Tigers<br />
Elephants<br />
Monkeys<br />
Giraffes<br />
Country Tally Frequency<br />
France 5<br />
Spain 7<br />
England 4<br />
Italy 4<br />
8 a <strong>The</strong> first question does not allow for people who<br />
never visit the park and it is hard to decide what each<br />
category means.<br />
<strong>The</strong> second question has overlapping categories.<br />
b On average, how often do you go to the County<br />
Park each month?<br />
Never 1–3 times 4–6 times<br />
more than 6 times<br />
How old are you?<br />
0–10 years 11–20 years Over 20 years<br />
9 a Biased, because it only includes those working on the<br />
night shift.<br />
b Not biased, because it uses a simple random<br />
sample.<br />
c Biased because the question starts with ‘Do you<br />
agree…’<br />
10 6 girls<br />
11 12 boys<br />
12 a 5 students b 26 students<br />
13 19 students<br />
14<br />
London York Total<br />
Boys 23 14 37<br />
Girls 19 24 43<br />
Total 42 38 80<br />
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<strong>Answers</strong><br />
Chapter 7 <strong>Answers</strong><br />
7.1 Get Ready<br />
1 a 150 g b 3 cm c 5 m d 300 ml<br />
Exercise 7A<br />
1 a 600 cm b 21 cm c 510 cm<br />
d 84 cm e 5.9 cm f 48.3 cm<br />
g 300 000 cm h 6700 cm<br />
2 a 3000 kg b 8200 kg c 6 kg<br />
d 0.9 kg e 0.43 kg f 4.7 kg<br />
3 a 2 litres b 7 litres c 5.9 litres<br />
d 45 litres<br />
4 7 litres<br />
Exercise 7B<br />
1 8.8 pounds<br />
2 50 kg<br />
3 4 litres<br />
4 8 gallons<br />
5 17.5 pints<br />
6 360 cm<br />
7 60 miles<br />
8 96 km<br />
9 585p per gallon<br />
Exercise 7C<br />
1 a 80 ounces b 6 pounds<br />
2 180 inches<br />
3 a 132 pounds b 60 kg<br />
7.2 Get Ready<br />
1 60 minutes<br />
2 1_ 4<br />
3 0.6<br />
4 18 minutes<br />
5 5 hours 42 minutes<br />
6 7 hours 42 minutes<br />
Exercise 7D<br />
1 a 13 km/litre b 6 litres<br />
2 a 240° b 30 seconds<br />
3 a 60 litres/min b 18 minutes 30 seconds<br />
4 0.0625 litre<br />
7.3 Get Ready<br />
1 a 18 km/l b 6.5 km/l c 13.2 km/l<br />
Exercise 7E<br />
1 4.24 km/h 2 10 km/h<br />
3 1 hour 12 minutes 4 306 km/h<br />
5 <strong>The</strong> speed for the 100 m was 10.32 m/s. <strong>The</strong> speed for the<br />
200 m was 10.36 m/s. <strong>The</strong> 200 m race was won with the<br />
faster average speed.<br />
7.4 Get Ready<br />
1 a 8.3 b 13.3 c 26.0 d 12.9<br />
Exercise 7F<br />
1 2.5 g/cm 3 2 0.777 cm 3 3 1.96 g/cm 3<br />
4 <strong>The</strong> aluminium block has the greater mass by 155 kg.<br />
Review exercise<br />
1 a 110 m, 70 g, 40 litres b 400 cm c 1.5 kg<br />
2 No, 1.5 km is 1500 m.<br />
3 80 km/hour<br />
4 432 miles/hour<br />
5 John’s speed: 20 km/hour. Kamala’s speed: 21 km/hour.<br />
Kamala had the greater average speed.<br />
6 320 seconds<br />
7 1.14 g/cm 3<br />
8 1930 g<br />
Chapter 8 <strong>Answers</strong><br />
8.1 Get Ready<br />
1 Not necessarily, one could be an enlargement of the other.<br />
2 No<br />
3 No<br />
Exercise 8A<br />
1 QS is the hypotenuse of both triangles<br />
angle QPS angle SRQ 90° (given)<br />
PS QR (given)<br />
So the triangles are congruent (RHS)<br />
2 angle YZX angle WVX (alternate angles)<br />
angle ZYX angle VWX (alternate angles)<br />
YZ WV (given)<br />
So the triangles are congruent (AAS)<br />
And YX XW, so X is the mid-point of WY<br />
3 PQ PR (given)<br />
QS RT (given)<br />
angle PQS angle PRT (isosceles triangle)<br />
So triangle PQS is congruent to triangle PRT (SAS)<br />
<strong>The</strong>refore PS PT and so triangle PST is isosceles<br />
4 Let the point where the line from L cuts the base at right<br />
angles be X.<br />
Now LM LN (given)<br />
LX is common to both triangles<br />
angle LXM angle LXN 90° (given)<br />
So triangles LMX and LNX are congruent (RHS)<br />
As the triangles are congruent then MX NX, so the line<br />
from L bisects the base.<br />
5 AD DB (as D is the midpoint of AB)<br />
angle ADE angle DBF (corresponding angles)<br />
angle DAE angle BDF (corresponding angles)<br />
So the triangles ADE and DBF are congruent (AAS)<br />
8.2 Get Ready<br />
When you fold it over, the star fits exactly on top of itself.<br />
When you rotate the star, it fits exactly on top of itself in four<br />
different positions.<br />
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<strong>Answers</strong><br />
Exercise 8B<br />
1 a Yes b Yes<br />
b e.g.<br />
c No<br />
d No<br />
e Yes f No<br />
c e.g.<br />
2 a No rotational symmetry<br />
b Rotational symmetry of order 2<br />
c Rotational symmetry of order 3<br />
d Rotational symmetry of order 8<br />
e No rotational symmetry<br />
f Rotational symmetry of order 2<br />
3 a<br />
8.3 Get Ready<br />
1 a i An isosceles triangles has two sides the same length<br />
and two angles the same.<br />
ii An equilateral triangle has all three sides the same<br />
length and all three angles the same.<br />
b Yes<br />
2 A polygon with four sides.<br />
Exercise 8C<br />
1 a<br />
4 a<br />
Line of<br />
symmetry<br />
b Isosceles triangle<br />
b It is also an isosceles triangle.<br />
2 a No. It could be a rectangle, square, rhombus,<br />
parallelogram, trapezium or isosceles trapezium.<br />
b No. It could be a rectangle, rhombus or parallelogram.<br />
c No. It could be a rectangle or rhombus.<br />
d Yes. It is a rectangle.<br />
3 e.g.<br />
b<br />
4 e.g.<br />
Rotational symmetry of order 2<br />
8.4 Get Ready<br />
A and C<br />
5 a e.g.<br />
Exercise 8D<br />
1 a Similar b Not similar<br />
2 All corresponding angles are equal so the pentagons are<br />
similar<br />
(angle CDE angle HIJ 150°)<br />
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<strong>Answers</strong><br />
Exercise 8E<br />
1 15 cm<br />
2 a 5.14 cm b 0.448 m<br />
3 15 cm<br />
8.5 Get Ready<br />
By inspection<br />
Exercise 8F<br />
1 a i AC and FE, BC and DF, AB and DE<br />
ii angle ABC angle EDF, angle BCA angle DFE,<br />
angle BAC angle DEF<br />
b i JK and GH, KL and HI, JL and GI<br />
ii angle KJL angle HGI, angle JKL angle GHI,<br />
angle KLJ angle HIG<br />
c i PN and MN, QN and ON, PQ and MO<br />
ii angle NPQ angle NMO, angle PQN angle NOM,<br />
angle PNQ angle MNO<br />
d i SR and WU, ST and WT, RT and UT<br />
ii angle STR angle UTW, angle RST angle TWU,<br />
angle SRT angle TUW<br />
2 a 5.525 cm b 7.225 cm<br />
3 a angle DEB angle ACB (given)<br />
angle DBE angle ABC (same angle)<br />
<strong>The</strong>refore angle BDE angle BAC (angles in a triangle)<br />
So triangle ABC is similar to triangle DBE<br />
b 6.46 cm c 2.26 cm d 1.99 cm<br />
4 a angle BDE angle BAC (given)<br />
angle DBE angle ABC (same angle)<br />
<strong>The</strong>refore angle DEB angle ACB (angles in a triangle)<br />
So triangle ABC is similar to triangle DBE<br />
b 6.36 cm c 10 cm<br />
5 a angle ABM angle CDM (alternate angles)<br />
angle BAM angle DCM (alternate angles)<br />
angle AMB angle CMD (vertically opposite angles)<br />
So triangle ABM is similar to triangle CDM<br />
b i 8 cm ii 12 cm<br />
Review exercise<br />
1 a b<br />
2 A and C<br />
3 Y and Z<br />
4 a angle ADB angle ADC 90° (given)<br />
AB AC (sides of equilateral triangle)<br />
AD is common<br />
So triangle ADC is congruent to triangle ADB (RHS)<br />
b BD CD (corresponding sides)<br />
BD CD BC AB<br />
So BD 1_<br />
2 BC<br />
5 AB BC (given)<br />
AD CD (given)<br />
BD is common<br />
So triangle ADB is congruent to triangle CDB (SSS)<br />
6 angle ACB angle CED (vertically opposite angles)<br />
angle CAB angle CED (alternate angles)<br />
angle ABC angle EDC (alternate angles)<br />
So triangle ABC is similar to triangle EDC<br />
a 12 cm b 9 cm<br />
7 12.5 cm<br />
8 a angle HJI angle GJF (same angle)<br />
angle IHJ angle FGJ (corresponding angles)<br />
angle HIJ angle GFJ (corresponding angles)<br />
So triangle HIJ is similar to triangle GFJ<br />
b 3.43 cm<br />
9 angle CAD angle BAE (same angle)<br />
angle ACD angle ABE (corresponding angles)<br />
angle ADC angle AEB (corresponding angles)<br />
So triangle ACD is similar to triangle ABE<br />
a 2 cm b 5.25 cm<br />
Chapter 9 <strong>Answers</strong><br />
9.1 Get Ready<br />
1 a 10x b 12x 2 c 2x 2<br />
d x 4 e x 2 5x 6<br />
f x 2 3x 2<br />
Exercise 9A<br />
1 a 2x 6 b 3p 6 c 4m 4n<br />
d 15 3q e 4x 2y 6 f 10c 5<br />
g 4x² 8 h 3n² 6n 3<br />
2 a y² 2y b g 2 3g c 2x 2 10x<br />
d 4n n 2 e ab ac f 3s 2 4s<br />
g 6t² 3t h 4x 3 12x 2<br />
3 a 2m 6 b 6x 6 c m 2 5m<br />
d 8y 2 12y e 5p 10 f 3q 3q 2<br />
g 2s 2 6s h 12mn 3n 2 15n<br />
Exercise 9B<br />
1 a 8t 3 b 9p 6 c 11w 6<br />
d 7d 2 e 5a 3b f 5x 3y 5<br />
2 a y 20 b 9a 6 c 4x 15<br />
d q 2 3 e 5n f 11m² 2m<br />
3 a t 16 b x 19 c g² g<br />
d 13c 2 22c e 4s² 14s 2 f p² q 2<br />
4 a 3s 4 b 15m 6 c 5f 2 3f<br />
d n 2 4n e 2x x 2 xy f 2p 2 5p<br />
9.2 Get Ready<br />
1 a 2 b 5 c 4 d 3y<br />
Exercise 9C<br />
1 a 3(x 2) b 2(y 1) c 5(p 2q)<br />
d 7(2t 1) e 2(4s t) f 9(a 2b)<br />
g 5(3u v 2w) h t(x y)<br />
i c(a 1) j 3(2x 2 3x 1)<br />
648<br />
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<strong>Answers</strong><br />
k 2p(p 1) l q(q 1) m x(4x 3)<br />
n h(2 5h) o p(p 2 2) p s 2 (1 s)<br />
2 a 5x(y t) b 3a(d 2c) c 2p(3q 2h)<br />
d 4y(2x 1) e 2p(2q s 4t)<br />
f mn(1 k) g 2x(x 2) h 12s(s 2)<br />
i 2f 2 (3 f) j y 2 (y 2 1) k cd(3d 5c)<br />
l ab (a 2 b 2 ) m 2pr(4q 5s) n 7ab(2a b 3)<br />
o 5x 2 y(3 7y) p 3y(3y 1)<br />
Exercise 9D<br />
1 a (x 3)(x 5) b (x y)(x y)<br />
c p(p 1) d (2t s)(2t s 1)<br />
e (a 5) (a 7) f 2(2d 1)(d 1)<br />
2 a 2(y 2)(y 4) b 5(x 1)(3x 5)<br />
c 2(p 5)(4p 25) d 3(q 1)(2q 5)<br />
e 7(a b) (a b 2) f 2x(x 1) (2x 3)<br />
9.3 Get Ready<br />
1 24 cm 2 2 x (x 2)<br />
Exercise 9E<br />
1 a x² 7x 12 b x² 3x 2<br />
c x² 3x 10 d y² y 6<br />
e y² y 2 f x² 5x 6<br />
g a² 9a 20 h x² 4x 4<br />
i p² 8p 16 j k² 14k 49<br />
k a² 2ab b² l a² 2ab b²<br />
2 a 2x² 3x 1 b 3x² 2x 1<br />
c 2x² 11x 12 d 3y² 8y 3<br />
e 2p² 7p 3 f 6t² 7t 2<br />
g 6s² 19s 10 h 4x² 4x 15<br />
i 12y² 5y 2 j 6a² 7a 2<br />
k 9x² 12x 4 l 4k² 4k 1<br />
3 a x² 3xy 2y² b x² xy 2y²<br />
c x² xy 2y² d x² 3xy 2y²<br />
e 6p² 7pq 3q² f 6s² 7st 2t²<br />
g 4a² 12ab 9b² h 4a² 12ab 9b²<br />
9.4 Get Ready<br />
1 a 1 and 6, 6 and 1, 2 and 3, 3 and 2<br />
b 1 and 15, 1 and 15, 3 and 5, 3 and 5<br />
2 5 and 2<br />
3 3 and 5<br />
Exercise 9F<br />
1 a 3, 5 b 6, 4 c 6, 3<br />
d 4, 2 e 4, 2 f 3, 3<br />
2 a (x 3)(x 5) b (x 1)(x 7) c (x 4)(x 5)<br />
d (x 3) 2 e (x 1)(x 5) f (x 1)²<br />
g (x 3)(x 6) h (x 6)(x 3) i (x 4)(x 7)<br />
j (x 4)(x 3) k (x 4)(x 6) l (x 2)(x 2)<br />
m (x 9)(x 9)<br />
Exercise 9G<br />
1 a (x 6)(x 6) b (x 7)(x 7)<br />
c (y 12)(y 12) d (5 y)(5 y)<br />
e (w 50)(w 50) f (100 a)(100 a)<br />
g (x 1)(x 3) h y(18 y)<br />
i 4ab<br />
2 a 2800 b 50 c 0.75 d 20 000<br />
3 a (2x 7)(2x 7) b (3y 1)(3y 1)<br />
c (11t 20)(11t 20) d (q 1)(q 3)<br />
e 8t f 4(p q)<br />
g 4(5p q 2)(5p q 3)<br />
h 100st<br />
4 a 3(x 2)(x 2) b 5(y 5)(y 5)<br />
c 10(w 10)(w 10) d 4(p 4q)(p 4q)<br />
e 3(2a 3b)(2a 3b) f 8x<br />
Exercise 9H<br />
1 a (5x 1)(x 3) b (2x 1)(x 5)<br />
c (3x 1)(x 1) d (4x 1)(2x 1)<br />
e (3x 2)(2x 3) f (6x 1)(x 1)<br />
g (5x 2)(x 1) h (4x 1)(3x 2)<br />
i (4x 3)(2x 1) j (2x 3)(x 5)<br />
k (7x 2)(x 3) l (3x 2)(x 4)<br />
m (2y 1)(2y 5) n (6y 1)(y 2)<br />
o (3y 5)(2y 5)<br />
2 a 2(3x 4)(x 1) b 3(2y 1)(y 2)<br />
c 5(x 2)(x 1)<br />
3 a (x y)(x 2y) b (x y)(2x 5y)<br />
c (3x 2y)(2x 3y)<br />
Review exercise<br />
1 5x 2<br />
2 a 5(m 2) b y(y 3)<br />
3 a (a b)(x y) b (a b)(c d)<br />
4 x 2 x 12<br />
5 a a 2 4a 4 b c 2 6c 9<br />
c d 2 2d 1 d x 2 2xy y²<br />
6 a x² 15x 50 b y² 18y 81<br />
c x² 2x 8 d x² x 6<br />
e t² 7t 6 f 2x² 11x 12<br />
g 6p² p 1 h 4c² d²<br />
i 16y² 8y 1<br />
7 a (t 5)(t 6) b (x 7)² c (p 5)(p 3)<br />
d (y 6)² e (x 4)(x 1) f (s 8)(s 8)<br />
8 a (x 1)(x 7) b 11 17<br />
9 2(Y 3), 26 red flowers<br />
10 a (x 20)(x 20) b (3t 2) (3t 2<br />
c (10 y)(10 y) d (5 2p)(5 2p)<br />
11 a 41 b 1.99 c 16<br />
12 8000<br />
13 Three consecutive numbers are n, n 1, n 2.<br />
(n 1)(n 2) n(n 1) (n 2 3n 2) (n 2 n)<br />
2n 2 2(n 1)<br />
14 6(x 2)<br />
15 a Each team plays 3 games at home against the other<br />
teams.<br />
So total number of games 4 3 12<br />
b 380 c a 2 a a(a 1)<br />
16 a (2x 1)(x 2) b (2w 1)(w 3)<br />
c (3a 2)(a 4) d (3z 2)(10z 1)<br />
e (8y 1)(y 3) f (3p q)(2p q)<br />
649<br />
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<strong>Answers</strong><br />
17 Let the top left number in the 2 by 2 square be n.<br />
n n 1<br />
n 6 n 7<br />
Difference of products from opposite corners<br />
(n 1)(n 6) n(n 7) (n 2 7n 6) (n 2 7n)<br />
6<br />
Chapter 10 <strong>Answers</strong><br />
10.1 Get Ready<br />
1 5 cm, 45 cm 2<br />
Exercise 10A<br />
1 a 40 cm 2 b 18 m 2 c 35 cm 2<br />
d 54 mm 2 e 30 cm 2 f 54 cm 2<br />
2 Area 15 cm 2 , area 25 cm 2 , base 6 cm, area 32 cm 2 ,<br />
height 8 cm<br />
3 a 5 cm b 12 cm<br />
Exercise 10B<br />
1 a 56 cm 2 b 96 m 2 c 75 cm 2 d 98 cm 2<br />
10.2 Get Ready<br />
a A lw<br />
b A l 2<br />
c A 1_<br />
2 bh<br />
d A bh<br />
e A 1_ (a b)h<br />
2<br />
Exercise 10C<br />
1 a 28 m b 37 m 2<br />
2 60<br />
3 30<br />
4 6 cm<br />
5 a i 32 m 2 ii 14 m 2<br />
b 24 m c 13 d 9<br />
6 a 66 cm b 234 cm 2<br />
7 30 cm 2<br />
8 100 cm 2<br />
Exercise 10D<br />
1 a 22.0 cm b 40.5 mm c 17.6 cm<br />
d 126 cm e 68.8 m<br />
2 a 145 cm b 25.1 cm<br />
3 6.00 cm<br />
4 a 210 cm b 2.1 km c 2859<br />
5 a 7.54 cm<br />
b i 45.2 cm ii 2.51 cm<br />
6 a 408 cm b 14.6 cm<br />
7 71.7 cm<br />
Exercise 10E<br />
1 a 201 cm 2 b 507 cm 2 c 2550 mm 2<br />
d 297 cm 2 e 499 m 2<br />
2 a 452 cm 2 b 54.1 cm 2 c 0.709 m 2<br />
d 2680 mm 2 e 262 cm 2<br />
3 a 19.6 m 2 b 18.8 m 2 c £36.80<br />
4 a 10 800 m 2 b £2480<br />
5 70.7 cm 2<br />
6 13 cm<br />
7 193 cm 2<br />
10.4 Get Ready<br />
1 a b c d<br />
Exercise 10F<br />
1<br />
2 Any six out of:<br />
10.3 Get Ready<br />
1<br />
Segment<br />
Chord<br />
Diameter<br />
Radius<br />
Tangent<br />
Sector<br />
Arc<br />
650<br />
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<strong>Answers</strong><br />
3 a Cylinder b Cone<br />
c Triangular-based pyramid d Square-based pyramid<br />
4 a e.g.<br />
Exercise 10G<br />
1 a<br />
Plan<br />
3 cm<br />
Front elevation<br />
Side elevation<br />
3 cm<br />
b<br />
Plan<br />
5 cm<br />
b e.g.<br />
5 cm<br />
2 cm<br />
3 cm<br />
6 cm<br />
Front elevation<br />
Side elevation<br />
6 cm<br />
c<br />
Plan<br />
10.5 Get Ready<br />
1 a<br />
4 cm<br />
5 cm<br />
5 cm<br />
3 cm<br />
d<br />
5 m<br />
5 m<br />
Front elevation<br />
Plan<br />
3 m<br />
2 m 2 m<br />
3 m<br />
Side elevation<br />
3 cm<br />
above<br />
side<br />
6 m<br />
3 cm<br />
2 m<br />
3 cm<br />
5 m<br />
5 m<br />
b<br />
4 cm<br />
cm<br />
2 cm<br />
cm<br />
front<br />
4 cm<br />
cm<br />
4 cm<br />
cm<br />
3 cm<br />
cm<br />
e<br />
2 m<br />
Front elevation<br />
Plan<br />
4 cm<br />
6 cm<br />
6 m<br />
Side elevation<br />
3 cm<br />
]<br />
3 cm<br />
cm<br />
2 cm<br />
cm<br />
above<br />
above<br />
6 cm<br />
cm<br />
front<br />
front<br />
side<br />
side<br />
5 cm<br />
4 cm<br />
6 cm<br />
Front elevation<br />
3 cm<br />
3 cm<br />
Side elevation<br />
5 cm<br />
651<br />
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<strong>Answers</strong><br />
f<br />
Plan<br />
10.8 Get Ready<br />
5 cm<br />
1 a 28.3 cm 2 (3s.f.) b 19.6 cm 2 (3s.f.)<br />
c 314 cm 2 (3s.f.)<br />
Exercise 10J<br />
4 cm<br />
2 cm<br />
Front elevation<br />
5 cm<br />
Side elevation<br />
4 cm<br />
1 a 251 cm 3 b 13 600 000 mm 3<br />
c 236 cm 3 d 8930 cm 3<br />
2 a 360 cm 3 b 650 cm 3<br />
c 0.101 25 m 3<br />
3 1600 m 3<br />
4 114.4 cm 3<br />
5 31.92 mm<br />
6 3.56 m 3 3560 litres<br />
g<br />
Plan<br />
4 cm<br />
Review exercise<br />
1<br />
5 cm<br />
8 cm<br />
Front elevation<br />
5 cm<br />
8 cm<br />
Side elevation<br />
2 a b<br />
c<br />
10.6 Get Ready<br />
1 a 192 m 3 b 576 cm 3<br />
Exercise 10H<br />
1 a 396 cm 3 b 378 cm 3 c 204 cm 3<br />
2 400 cm 3<br />
10.7 Get Ready<br />
1 a a 3 b 2a 3 c a 3<br />
Exercise 10I<br />
1 a 78 cm 3 b 2250 mm 3 c 0.498 75 m 3<br />
d 216 cm 3<br />
2 a 225 cm 3 b 10 500 cm 3 c 80.43 cm 3<br />
d 84 000 cm 3<br />
3 9 cm<br />
4 Volume 1_<br />
2 (x 3x) 2x 2x 8x3 cm 3<br />
5 h 4.5y<br />
2 20 cm 3<br />
3 70 cm 2<br />
4 a b<br />
5 5 cm<br />
6 150 boxes<br />
652<br />
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<strong>Answers</strong><br />
7 a 5 cm b i 19 boxes ii 8 chocolates<br />
8 a 118.12 cm 2 b 83.52 cm 3<br />
9 a<br />
6 cm<br />
9 cm<br />
4.5 cm<br />
Plan<br />
6 cm<br />
9 cm<br />
4.5 cm<br />
Front elevation<br />
Side elevation<br />
b 189 cm 2<br />
10 Skirting board: 3 4 2 2 1, therefore cheapest<br />
3 £30.50 1 £18.75 1 £14.00 £124.25<br />
Coving: 20 m, therefore cheapest<br />
6 £27.50 1 £22.00 £187.00<br />
Total £311.25<br />
11 Area 28 m 2 , therefore ___ 550 £19.64 to spend per m2<br />
28<br />
Amy can afford Natural Twist with either underlay or<br />
Medium Blend with Cushion.<br />
12 Paving 20 £40 £800, grass 110 £15 £1650,<br />
total £2450<br />
13 2 2.55 16 m 32 roses, so cost £134.40<br />
14 Area 4 4 (4 1 0.5 1 1.8 1 2 )<br />
7.958 m 2<br />
Cost 7.958 4.60 £36.61<br />
15 a Volume of cup ____________<br />
10 4.52<br />
159 ml, so the cup<br />
4<br />
can hold 150 ml.<br />
b Volume of squash required 30 150 3 13 500 ml<br />
13.5 litres<br />
1 bottle makes 0.8 7 5.6 litres<br />
___ 13.5<br />
2.4, so 3 bottles are needed.<br />
5.6<br />
c £3.75<br />
16 a 700 cm 3 b 13.51 kg<br />
17 Volume __ 25<br />
2 (1 3) 10 500 m3 ,<br />
so time 250 minutes 4 hours 10 minutes<br />
18 a 308.5 m<br />
b Add 45.8 m to the straights making each one 105.8 m or<br />
add 29.1 m to the diameter of the bends, making each<br />
diameter 89.1 m<br />
19 200 50 1 2 42.9 cm 2<br />
20 Volume of oil 60 2 180 2 036 752 cm 3 ,<br />
so mass of oil 8754 kg<br />
Surface area of tank 2r 2 2rh 90 478 cm 2 ,<br />
so mass of tank 253 kg<br />
Total mass 9007 kg 9 tonnes<br />
21 a 315 cm 3 b 0.6 g/cm 3<br />
Chapter 11 <strong>Answers</strong><br />
11.1 Get Ready<br />
1 a 1 2 3 4 5 5 7 8 8 9 10 12 b 3.5, 3.5, 4.5, 4.6, 6.2, 8.7, 12.5<br />
Exercise 11A<br />
1 2<br />
2 16 litres<br />
3 a 16 b 16<br />
4 227<br />
11.2 Get Ready<br />
1 a 44 b 20.4<br />
Exercise 11B<br />
1 3<br />
2 a 136 b 134<br />
3 £1292<br />
4 a 10 b 20 c 24<br />
11.3 Get Ready<br />
a Median 20<br />
Mode 20<br />
b Mean 21 to 2 s.f.<br />
Exercise 11C<br />
1 a Mean £47, mode £17, median £22<br />
b <strong>The</strong> median is best. <strong>The</strong> mean has been affected by one<br />
high value and the mode is the lowest value.<br />
2 One advantage from: Is the most popular measure. Can<br />
be used for further calculations. Uses all the data. One<br />
disadvantage from: Affected by extreme values. Actual<br />
value may not exist.<br />
3 a 28 b 38<br />
c 64 (to the nearest whole person)<br />
d <strong>The</strong> mean because it is the highest average.<br />
11.4 Get Ready<br />
Number 1 2 3 4 5 6<br />
Frequency 1 4 4 3 3 1<br />
Exercise 11D<br />
1 a Frequency number of siblings: 0, 8, 18, 12, 12, 0, 12, 7<br />
Total f 30<br />
Total f x 69<br />
b 2 c 2 d 2.3<br />
2 a 104 b 104 c 104<br />
3 a 17 b 18 c 18.5<br />
11.5 Get Ready<br />
Class interval<br />
Frequency<br />
1–4 11<br />
5–9 5<br />
10–14 7<br />
15–19 7<br />
653<br />
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<strong>Answers</strong><br />
Exercise 11E<br />
1 a 70.0 x 70.1 b 69.9 x 70.0<br />
2 a £281£320 b £321£360<br />
3 a 0.45 x 0.50 b 0.40 x 0.45<br />
11.6 Get Ready<br />
a 60 b 0.8 c 0.000 55<br />
Exercise 11F<br />
1 42.5 2 181.0 seconds 3 54.23 seconds<br />
11.7 Get Ready<br />
1 14 16 16 18 21 23 27 32 38 43 45 49<br />
2 36.0 kg 43.4 kg 43.5 kg 49.9 kg 56.2 kg 56.2 kg<br />
Exercise 11G<br />
1 Median<br />
2 a Q 1 50, Q 2 62, Q 3 70 b 20 c 42<br />
3 a Q 1 8, Q 2 13, Q 3 19 b 11 c 19<br />
4 a Q 1 32, Q 2 45, Q 3 52 b 20 c 47<br />
Review exercise<br />
1 a 3.5 b 3.6 c 4<br />
2 a Mode £4, median £5, mean £9<br />
b <strong>The</strong> median, because the mode is close to the<br />
lowest value and the mean is affected by the<br />
single large amount of £38.<br />
3 a One advantage from: unaffected by extreme values;<br />
can be used with qualitative data.<br />
One disadvantage from: may be more than one mode;<br />
may not be a mode.<br />
b Advantage: not influenced by extreme values.<br />
Disadvantage: actual value may not exist.<br />
c One advantage from: can be used for further<br />
calculations; uses all the data.<br />
Disadvantage: affected by extreme values.<br />
4 a 86 b 3.6<br />
5 a <strong>The</strong> mode is 7, the number of rooms that occurs most<br />
frequently. Ali has given the maximum number of rooms.<br />
b 6.3 to 1 d.p.<br />
6 2.4 to 1 d.p.<br />
7 45<br />
8 7.7<br />
9 a 10.5–10.7 b 10.2–10.4<br />
10 a<br />
Class Interval Frequency<br />
(f)<br />
Class<br />
mid-point<br />
f x<br />
26 w 29 4 27.5 110<br />
29 w 32 7 30.5 213.5<br />
32 w 35 15 33.5 502.5<br />
35 w 38 12 36.5 438<br />
38 w 41 2 39.5 79<br />
Totals 40 1343<br />
b 33.6 kg to 3 s.f.<br />
11 84.8 mm to 3 s.f.<br />
12 19 minutes<br />
13 a 30 t 40 b 27.4 minutes<br />
14 13.0 minutes to 3 s.f.<br />
15 Year 11 – 26 pets (Year 9 – 76 pets, Year 10 – 72 pets)<br />
16 a Q 1 42 kg, Q 2 47 kg, Q 3 49 kg<br />
b 7 kg<br />
c 11 kg<br />
17 a 18 minutes b 15 minutes<br />
c Before: Q 1 14 minutes, Q 3 22 minutes<br />
After: Q 1 11 minutes, Q 3 19 minutes<br />
d Before: interquartile range 8 minutes<br />
After: interquartile range 8 minutes<br />
e Before the introduction of the traffic management<br />
scheme the mean time taken to travel to work was<br />
higher than after the scheme was introduced. <strong>The</strong><br />
interquartile range stayed the same, so the spread of<br />
times was similar before and after the scheme started.<br />
18 Mean ______ 300 000<br />
£30 000. <strong>The</strong> owner could say that the<br />
10<br />
average salary is £30 000 and it is high enough.<br />
Mode/median £10 000. <strong>The</strong> workers could say that the<br />
average salary is £10 000 and too low.<br />
19 If 1 dog in 100 had three legs, then the mean number of<br />
legs ___ 399<br />
100 3.99<br />
<strong>The</strong> majority of dogs have four legs.<br />
Chapter 12 <strong>Answers</strong><br />
12.1 Get Ready<br />
Students' accurate drawings<br />
Exercise 12A<br />
1–5 Students' drawings<br />
6 <strong>The</strong> sum of the two shorter sides is less than the longest<br />
side.<br />
12.2 Get Ready<br />
1<br />
2<br />
3<br />
A<br />
4 cm<br />
6 cm<br />
5 cm 5 cm<br />
B<br />
654<br />
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<strong>Answers</strong><br />
Exercise 12B<br />
1<br />
5 cm 4 cm<br />
3 a b c<br />
2 a<br />
B<br />
b<br />
A<br />
d<br />
e<br />
P<br />
P<br />
4<br />
A<br />
B<br />
4 cm<br />
3<br />
P<br />
5<br />
Q<br />
4 cm<br />
12.3 Get Ready<br />
1<br />
3 cm<br />
12.4 Get Ready<br />
1<br />
3 cm<br />
2,3<br />
60°<br />
any points<br />
on this circle<br />
Exercise 12C<br />
2<br />
1 a<br />
A<br />
b B<br />
C<br />
A<br />
B<br />
B<br />
C<br />
A<br />
3<br />
2 a R<br />
any points<br />
on this line<br />
Exercise 12D<br />
Q<br />
P<br />
1 3 cm<br />
A<br />
B<br />
b<br />
Q<br />
2<br />
3.5 cm<br />
P<br />
R<br />
P<br />
655<br />
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<strong>Answers</strong><br />
3<br />
4<br />
P<br />
5 cm<br />
1.5 cm<br />
Exercise 12F<br />
1 a 1 cm represents 2 km<br />
b i 6 km ii 9.5 km iii 4.2 km<br />
2 a 13.5 cm b 312 km<br />
3 b 14.4 km c 146°<br />
4<br />
Q<br />
R<br />
12.5 Get Ready<br />
1<br />
3 cm<br />
any points<br />
inside this circle<br />
2<br />
A<br />
B<br />
any points<br />
this side of the<br />
perpendicular<br />
bisector of AB<br />
5 a 1 : 50 b 10 cm<br />
6 a 1 : 5 000 000 b 3.66 cm<br />
Review exercise<br />
3<br />
any points<br />
inside this region<br />
1 By inspection<br />
2 By inspection<br />
3 By inspection<br />
4 By inspection<br />
5 a 250 mm b 324 m<br />
6<br />
Beeham<br />
Corting<br />
Exercise 12E<br />
1<br />
2 cm<br />
P<br />
2<br />
4 cm<br />
2.6 cm<br />
7<br />
Alston<br />
A<br />
Deetown<br />
3<br />
4<br />
D<br />
G<br />
3 cm<br />
H<br />
E<br />
F<br />
B<br />
C<br />
5 1.4 m<br />
8 Construction of angle of 30° at P<br />
0.8 m<br />
9 a<br />
25 cm<br />
C<br />
8 cm<br />
D<br />
12.6 Get Ready<br />
1 a 50 km b 2.5 km<br />
2 a 400 000 cm b 30 000 cm<br />
b<br />
3 cm<br />
4.5 cm<br />
3 cm 3 cm<br />
3 cm<br />
656<br />
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<strong>Answers</strong><br />
10 a Students' drawings<br />
b 034° c 214°<br />
11 Construction of bisector of angle ABC<br />
12 A B<br />
C<br />
1.2 cm<br />
1 cm<br />
13 Construction of perpendicular bisector of a line 7 cm long<br />
14 Construction of perpendicular to the line ST from a point<br />
above the line M<br />
15 a Locus of centre of wheel<br />
16<br />
b<br />
Road<br />
Chapter 13 <strong>Answers</strong><br />
13.1 Get Ready<br />
1 a 4 2p 5q b 3 6z c 12m 2 36m<br />
Exercise 13A<br />
1 a 4 2 b 7<br />
3 c 2.5 4 d 1.8<br />
5 e 1.5 6 f 4<br />
7 g 6 8 h 0.5<br />
9 k 2.6 10 m 3.5<br />
13.2 Get Ready<br />
1 a x 6 b b 4 c q 8<br />
Exercise 13B<br />
1 x 3 2 y 3<br />
3 x 2.25 4 y 2<br />
5 x 0.25 6 w 4<br />
7 z 0.25 8 x 1_<br />
D<br />
__<br />
9<br />
3<br />
9 x 1 10 y 13<br />
13.3 Get Ready<br />
1 a x 8 b a 2 c b 2<br />
Exercise 13C<br />
1 a 2.5 2 b 2.5<br />
3 c 3 4 d 2<br />
5 e 1 6 f 9<br />
10 0.9<br />
7 x 15 8 x 2<br />
9 x 3 10 x 3_<br />
5 0.6<br />
13.4 Get Ready<br />
1 a x 2 b x 6_<br />
7 c x 0.9<br />
Exercise 13D<br />
1 p 20 2 q 10<br />
3 m 30 4 x 24<br />
5 y 53<br />
8 6 x 33<br />
7 n 5<br />
42 8 t 44<br />
9 x 6.5 10 y 76<br />
13.5 Get Ready<br />
1 a a 2 b b 1_<br />
2<br />
Exercise 13E<br />
1 x 5<br />
2 31<br />
3 Jessica 80%, Mason 60%, Zach 70%<br />
4 x 8<br />
5 23 1_<br />
4 hours<br />
3(x 6)<br />
6 a (x 4) _______ b 15 cm<br />
5<br />
7 149 units<br />
13.6 Get Ready<br />
1 a 6 b 2 c 4<br />
Exercise 13F<br />
43<br />
c x 11<br />
2_<br />
3<br />
1 formula 2 identity<br />
3 expression 4 equation<br />
5 formula 6 formula<br />
7 expression 8 equation<br />
9 formula 10 equation<br />
11 equation 12 identity<br />
Review exercise<br />
1 t 4.5<br />
2 x 4.5<br />
3 a x 2.5 b y 2.5<br />
4 58°<br />
5 57 cm<br />
6 Uzma £18, Hajra £38, Mabintou £76<br />
7 A £8, B £12, C £4<br />
8 x __ 44<br />
3<br />
9 x 5.5<br />
10 y 10<br />
14<br />
2_<br />
3<br />
657<br />
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<strong>Answers</strong><br />
Chapter 14 <strong>Answers</strong><br />
14.1 Get Ready<br />
1 a i 1_<br />
5<br />
ii 0.2 b i<br />
1_<br />
8<br />
c i 3_<br />
5<br />
ii 0.6<br />
7<br />
d i 40<br />
ii 0.125<br />
ii 0.175<br />
Exercise 14F<br />
1 a 1.728 b 0.6561 c 1.0608 d 0.52<br />
2 £1102.50<br />
3 a 1.1136 b £66 816<br />
4 No. It is the same as an increase of 68%.<br />
5 8 years<br />
Exercise 14A<br />
1 a £180 b 6 kg c £1.62 d 4.96 kg<br />
e £6 f 45 g 2.52 km h £52.50<br />
2 12<br />
3 £10<br />
4 1058<br />
7<br />
5 __<br />
22<br />
14.2 Get Ready<br />
1 £75 2 £16 3 1_ 4<br />
Exercise 14B<br />
1 a 1.64 b 1.03 c 1.14 d 1.4<br />
e 1.134 f 1.125 g 1.15 h 1.0236<br />
2 a 1.4 b £21.56<br />
3 Helen £12 504, Tom £25 008, Sandeep £33 344<br />
4 £621<br />
5 a £144 b 70 kg c 2.784 m<br />
d £1370.20 e 128.52 cm<br />
Exercise 14C<br />
1 a 0.93 b 0.8 c 0.84 d 0.73<br />
e 0.944 f 0.975 g 0.9275 h 0.992<br />
2 a £255 b £34 c £1020<br />
3 77.9 kg<br />
4 £748<br />
5 a £5840 b £4672<br />
14.3 Get Ready<br />
1 £12.75 2 £1300 3<br />
Exercise 14D<br />
1 a 50% b 25% c 40% d 20%<br />
e 25% f 25% g 60% h 12.5%<br />
2 90%<br />
3 45%<br />
4 a 20% b 60% c 11.25% d 8.75%<br />
Exercise 14E<br />
__ 9<br />
40<br />
1 a 50% b 60% c 12% d 8%<br />
2 15%<br />
3 40%<br />
4 Shop C – as percentage increases are<br />
A 5.19%, B 4.77%, C 5.50%<br />
5 20% profit<br />
6 2.7%<br />
14.4 Get Ready<br />
1 2 5 2 0.3 3 1.25<br />
14.5 Get Ready<br />
1 1.15 2 0.85 3 1.04 4 0.96<br />
Exercise 14G<br />
1 £24 000 2 £280 3 £620<br />
4 £180 5 421 000 6 £270<br />
Review exercise<br />
1 a £240 b 5 kg c 10.5 kg d £10.50<br />
2 16.7%<br />
3 18 years<br />
4 A (A £510, B £512, C £517.50)<br />
5 CompuSystems (Able £23 000, Beta £23 400,<br />
CompuSystems £24,240, Digital £24 000)<br />
6 72%<br />
7 £7800<br />
8 a 62.5% b<br />
1_<br />
4<br />
9 19.9%<br />
10 a It will be worth 32.8% of its original value.<br />
b 0.64<br />
11 £275<br />
12 £8400<br />
13 £1600<br />
14 £665<br />
15 B (A 9.2% over two years, B 9.2025% over two years)<br />
Chapter 15 <strong>Answers</strong><br />
15.1 Get Ready<br />
1 a 7 b 1<br />
2 a y 1 b y 1.5<br />
Exercise 15A<br />
1 a y<br />
5<br />
x 3<br />
4<br />
3<br />
2<br />
1<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
2<br />
3<br />
4<br />
5<br />
x<br />
658<br />
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<strong>Answers</strong><br />
b<br />
y<br />
5<br />
e<br />
y<br />
5<br />
x 1.5<br />
4<br />
4<br />
3<br />
2<br />
y 2<br />
3<br />
2<br />
1<br />
1<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
x<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
x<br />
2<br />
2<br />
3<br />
3<br />
4<br />
4<br />
5<br />
5<br />
c<br />
y<br />
5<br />
4<br />
3<br />
2<br />
1<br />
x 0<br />
f<br />
y<br />
5<br />
4<br />
3<br />
2<br />
1<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
2<br />
3<br />
4<br />
5<br />
x<br />
5 4 3 2 1 O 1 2 3 4 5 x<br />
1<br />
2<br />
3<br />
4<br />
y 5<br />
5<br />
d<br />
y<br />
5<br />
4<br />
3<br />
2<br />
1<br />
y 0<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
x<br />
2 a x 4 b y 2 c y 5 d x 1_<br />
2<br />
3 a (1, 3) b (4, 2) c ( 1_<br />
2 , 3)<br />
4 22 units, 28 units squared<br />
Exercise 15B<br />
1 a<br />
b<br />
x 2 1 0 1 2 3 4<br />
y 8 6 4 2 0 2 4<br />
y<br />
8<br />
2<br />
6<br />
3<br />
4<br />
4<br />
2<br />
5<br />
2 O 2 4<br />
2<br />
x<br />
4<br />
y 4 2x<br />
659<br />
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<strong>Answers</strong><br />
2 a y<br />
8<br />
6<br />
4<br />
2<br />
y 4x 8<br />
Exercise 15C<br />
1 y<br />
6<br />
4<br />
O<br />
2<br />
2 4<br />
x<br />
2<br />
3x 4y 12<br />
4<br />
6<br />
8<br />
4<br />
2<br />
O<br />
2 4<br />
x<br />
10<br />
2<br />
12<br />
b i (2, 0) ii (0, 8)<br />
c i 2 ii 3.5<br />
3 a y<br />
8<br />
2<br />
6<br />
4<br />
2<br />
O<br />
2<br />
4<br />
6<br />
8<br />
y 2x<br />
y x<br />
2<br />
y 3x<br />
x<br />
y x<br />
2 a y<br />
10<br />
5<br />
10 5 O<br />
5<br />
10<br />
5<br />
10<br />
x<br />
x y 7<br />
x y 2<br />
x y 4<br />
b <strong>The</strong>y are parallel to each other.<br />
3 y<br />
4<br />
2<br />
2x 3y 12<br />
b all pass through (0,0)<br />
4 a y<br />
40<br />
30<br />
20<br />
10<br />
4 3 2 1 O<br />
10<br />
20<br />
30<br />
40<br />
b (1.5, 0)<br />
5 y<br />
4 y x<br />
y 2x 5<br />
2<br />
y 0<br />
6 4 2 O 2 x<br />
2<br />
4<br />
6<br />
6.25 square units<br />
y 6x 9<br />
1 2 3 4<br />
x<br />
y 9 6x<br />
2<br />
(3, 2)<br />
2<br />
4 a y<br />
10<br />
O 2 4<br />
x y 1<br />
8<br />
6<br />
4<br />
2<br />
4 2 O<br />
2<br />
2<br />
2<br />
4<br />
x<br />
x<br />
5y 2x 8<br />
6<br />
2y 5x 20<br />
b <strong>The</strong>y intersect at right angles.<br />
c e.g. 2x 3y 6 and 3x 2y 12<br />
15.2 Get Ready<br />
a 5 b 5.5 c 17.25 d 0.225<br />
e 1 f 8.5<br />
660<br />
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<strong>Answers</strong><br />
Exercise 15D<br />
1 a (1, 2) b (3, 0.5) c (1.5, 3)<br />
d (2.5, 0.5) e (4, 0.5) f (0.5, 2)<br />
g (2.5, 0.5) h (0.5, 2.5) i (2, 3)<br />
j (4.5, 0.5)<br />
2 a (1.5, 0.5) b (4, 1) c (1.5, 1)<br />
d (3.5, 2.5)<br />
3 a (4, 4) b (2, 2.5) c (1.5, 3.5)<br />
d (3, 4.5) e (2, 2.5) f (2.5, 1.5)<br />
15.3 Get Ready<br />
1 y<br />
y 3x<br />
5<br />
4<br />
3<br />
2<br />
1<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
2<br />
3<br />
4<br />
5<br />
2 y<br />
5<br />
4<br />
3<br />
2<br />
1<br />
y 2x<br />
y x<br />
5 4 3 2 1 O 1 2 3 4 5 x<br />
1<br />
2<br />
1<br />
y <br />
2<br />
x<br />
3<br />
4<br />
5<br />
y 2x<br />
y x<br />
x<br />
3<br />
y<br />
y 3x<br />
5<br />
4<br />
3<br />
2<br />
1<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
Exercise 15E<br />
2<br />
3<br />
4<br />
5<br />
y 3x 2<br />
y 3x 3<br />
__ 10<br />
1 a 30 b 10 c<br />
3<br />
d 2_<br />
5 e 1_<br />
5 f __ 1<br />
40<br />
2 a 2, 3 b 2, 4<br />
c 4, 6<br />
d<br />
3_<br />
4 ,1<br />
3 a y<br />
b<br />
5<br />
4<br />
3<br />
2<br />
1<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
2<br />
3<br />
4<br />
5<br />
y<br />
5<br />
4<br />
3<br />
2<br />
1<br />
x<br />
y x 2<br />
y 2x 3<br />
x<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
2<br />
3<br />
4<br />
5<br />
x<br />
661<br />
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<strong>Answers</strong><br />
c<br />
d<br />
e<br />
y<br />
5<br />
4<br />
3<br />
2<br />
1<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
2<br />
3<br />
4<br />
5<br />
y<br />
5<br />
4<br />
3<br />
2<br />
1<br />
1<br />
y <br />
2x 4<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
2<br />
3<br />
4<br />
5<br />
y<br />
5<br />
4<br />
3<br />
2<br />
1<br />
y 3x 3<br />
1<br />
y <br />
3<br />
x 2<br />
x<br />
x<br />
b Gradient 1.8. This represents the number of degrees<br />
Fahrenheit for each degree Celsius.<br />
3 a A 15, B 10, C 4<br />
b <strong>The</strong> gradients represent speed. A is the car (the fastest<br />
vehicle), B is the lorry, C is the cycle (the slowest<br />
vehicle).<br />
4 a<br />
Depth (d cm)<br />
250<br />
200<br />
150<br />
100<br />
50<br />
0<br />
0 50 100 150 200 250<br />
Time (t seconds)<br />
b 5_<br />
6<br />
c <strong>The</strong> depth of water is going down by 5_ cm per second.<br />
6<br />
<strong>The</strong> swimming pool is being emptied.<br />
15.4 Get Ready<br />
1 2, 1_<br />
2 , 1<br />
<strong>The</strong> gradient is the same as the coefficient of x.<br />
2 1, 2, 2<br />
<strong>The</strong> y-intercept is the same as the value of the number in<br />
the equation.<br />
Exercise 15G<br />
1 y 2x 5<br />
2 a i 4 ii 1<br />
b i 3<br />
ii 4<br />
c i 2_<br />
3 ii 4<br />
d i 0.4 ii 4<br />
e i 1 1_ ii 4<br />
3<br />
f i 1_<br />
2 ii 0<br />
3 A y 2x 8 B y 1_<br />
3 x 2 C y 5 1_<br />
D y 4 x E y 2x 6<br />
4 y 5x 2<br />
5 y 3x 10<br />
2 x<br />
4 e.g. (3, 2)<br />
5 a 1_<br />
2<br />
Exercise 15F<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
b (0, 4)<br />
2<br />
3<br />
4<br />
5<br />
1 a Gradient 40. This represents the extra time needed<br />
(in minutes) for each extra kilogram of chicken.<br />
b Cooking time 40 minutes per kilogram plus 20 minutes<br />
c You can’t have a negative weight of chicken.<br />
2 a 50°F<br />
x<br />
15.5 Get Ready<br />
1 a 1_<br />
2 , 2 b 1_<br />
3 , 3 c 2_<br />
3 , 2_<br />
3<br />
In a and b the product of the gradients is 1.<br />
In c the gradients of the parallel lines are the same.<br />
Exercise 15H<br />
1 a 1_<br />
c 5 d <br />
1_<br />
3 e 6<br />
3 b 1_<br />
4<br />
2 a y 2x c for any value of c except 5<br />
b y 1_ x c for any value of c except 1<br />
3<br />
c y c x for any value of c except 4<br />
3 a y c x for any value of c<br />
b y c 1_ x for any value of c<br />
3<br />
c y 2x c for any value of c<br />
4 y 4x 3<br />
5 2x y 0<br />
6 y 4x<br />
7 y x 3<br />
662<br />
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15.6 Get Ready<br />
1 C 14:30, D 15:15, E 15:54<br />
Exercise 15I<br />
1 a 4 km b 75 minutes c 5 1_<br />
3 km/h<br />
d 6 minutes each time<br />
e 10 km/h<br />
2 a £2.75 b 2 kg c £12.20<br />
3 a<br />
b<br />
Review exercise<br />
1 a y<br />
5<br />
4<br />
3<br />
2<br />
1<br />
x 4<br />
<strong>Answers</strong><br />
Volume<br />
Volume<br />
5 4 3 2 1 O 1 2 3 4 5 x<br />
1<br />
y 2<br />
2<br />
3<br />
4<br />
y x<br />
Depth<br />
Depth<br />
5<br />
c<br />
d<br />
b 2 square units<br />
Volume<br />
Volume<br />
2<br />
16<br />
14<br />
12<br />
4 A b, B a, C c<br />
5<br />
15<br />
Depth<br />
Depth<br />
$<br />
10<br />
8<br />
6<br />
4<br />
2<br />
Petrol consumption (km/l)<br />
14.5<br />
14<br />
13.5<br />
13<br />
0<br />
0 2 4 6 8 10<br />
£<br />
3 a i 3 ii 1_<br />
2 iii 0<br />
b i 1_<br />
2<br />
ii 3<br />
4<br />
C 0 20 40 60 80 100<br />
F 30 70 110 150 190 230<br />
12.5<br />
12<br />
60 70 80 90 100 110<br />
Speed (km/h)<br />
a 13.5 km/l b 74 km/h, 97 km/h<br />
F<br />
250<br />
200<br />
150<br />
F 2C 30<br />
100<br />
50<br />
0<br />
0 10 20 30 40 50 60 70 80 90 100 C<br />
663<br />
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<strong>Answers</strong><br />
5 a y<br />
10<br />
8<br />
6<br />
4<br />
2x y 6<br />
2<br />
1<br />
O<br />
2 4 6<br />
x<br />
2<br />
4<br />
b i 2 ii 6<br />
6 a 120 km b 0.5 hour c 80 km/h<br />
d 18:52 e 48 km/h<br />
7 B (A gradient 2, B gradient 4, C gradient 2.5)<br />
8 a d b d<br />
V<br />
c d d d<br />
V<br />
9 a No b y 1_<br />
2 x 5 c y 2x 9<br />
10<br />
y<br />
10<br />
V<br />
V<br />
13<br />
Cost (£)<br />
500<br />
400<br />
300<br />
200<br />
100<br />
Hermes<br />
Atlantis<br />
0<br />
0 10 20 30 40 50 60 70 80<br />
Number of sessions<br />
If Abbie plans to go to the health club more than 50 times<br />
a year, she should choose Atlantis.<br />
14 (3, 2)<br />
15<br />
Equation of line Gradient y-intercept<br />
y 2x 5 2 5<br />
y 7x 3 7 3<br />
y 6 x 1 6<br />
y 2_<br />
3 x 1 2_<br />
3 1<br />
y 3 4x 4 3<br />
16 A: <strong>The</strong> temperature stays constant.<br />
B: <strong>The</strong> temperature rises at a constant rate.<br />
C: <strong>The</strong> temperature rises at a constant rate and then falls<br />
at a faster constant rate.<br />
D: <strong>The</strong> temperature stays the same and then falls at a<br />
constant rate.<br />
E: <strong>The</strong> temperature rises at a constant rate, stays the<br />
same for a period of time and then continues to rise at<br />
the same constant rate.<br />
F: <strong>The</strong> temperature rises at a constant rate, stays the<br />
same for a period of time and then falls at the same<br />
rate at which it rose.<br />
17 a Perimeter 2 (2x y) 24, so 2x y 12<br />
b y<br />
12<br />
8<br />
10<br />
6<br />
4<br />
2<br />
1 O 1<br />
2<br />
y 7 2x<br />
2 3 4<br />
11 a 4 b ( 3_ , 0) c 4.5<br />
4<br />
12 a From the top on the right-hand side: B, A, C<br />
b £40<br />
c C would be cheapest. (A £32, B £30, C £25)<br />
x<br />
8<br />
2x y 12<br />
6<br />
4<br />
2<br />
0<br />
0 1<br />
2 3 4 5 6<br />
c x 3<br />
18 k 7. x 3 in y 3x 2 gives y 7, so (3, 7) also lies<br />
on y 3x 2<br />
19 y 5 2x<br />
20 a 1_<br />
2 b y 2x 2<br />
x<br />
664<br />
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<strong>Answers</strong><br />
Chapter 16 <strong>Answers</strong><br />
16.1 Get Ready<br />
1 18 km<br />
Exercise 16A<br />
1 a 1 : 3 b 1 : 4 c 1 : 3.5 d 1 : 0.5<br />
e 1 : 0.3 f 1 : 0.6 g 1 : 8 h 1 : 8<br />
15<br />
2 1 : 5<br />
3 a<br />
4_<br />
9 b 4 : 5 c 1 : 1.25<br />
4 1 : 375<br />
5 a 1 : 1_<br />
6<br />
b 1 : 0.2 c 1 : 0.02 d 1 : 40<br />
16.2 Get Ready<br />
1 a 2 : 3 b 1 : 5 c 8 : 7 d 9 : 200<br />
Exercise 16B<br />
1 a 10 g b 30 g c 250 g<br />
2 a 10 kg b 15 kg<br />
3 108.5 km<br />
4 £1080<br />
5 1.53 m<br />
6 250<br />
16.3 Get Ready<br />
1 20.65 2 6 3 241.5<br />
Exercise 16C<br />
1 a £4.26 : £10.65 b 360 g : 240 g<br />
c £14.21 : £56.84 : £99.47 d 6.3 m : 12.6 m : 15.75 m<br />
2 60°, 50°, 70°<br />
3 £36.50<br />
7<br />
4 __<br />
16<br />
5 18<br />
6 £52<br />
16.4 Get Ready<br />
1 15 2 50p 3 80 mins 4 2.75<br />
Exercise 16D<br />
1 a 3 hours b 7 hours<br />
2 £64.05 3 £33.75 4 £4.50<br />
5 £3.24 6 70 cm<br />
Exercise 16E<br />
1 a 160 g b 150 g<br />
2 2 hours 20 minutes<br />
3 a $320 b £340<br />
4 £120<br />
5 America by $10.25<br />
6 $58.50<br />
16.5 Get Ready<br />
1 a 52 b 16 c 60 hours<br />
Exercise 16F<br />
1 a 4 days b 5 days<br />
2 2 hours 3 9 hours 4 9 days<br />
5 192 cm 6 8<br />
Review exercise<br />
1 3 : 2<br />
2 21 : 4<br />
3 5 : 2<br />
4 a 0.5 m b 16 m<br />
5 45 litres<br />
6 10<br />
7 110<br />
8 Local professional (local $652.50, USA $684)<br />
9 Small bottle (large 0.25 p/g, small 0.22 p/g)<br />
10 2.33 pm<br />
11 1.5 km 2<br />
12 a B b D<br />
c A and B, as they lie on the same line through the origin<br />
d D<br />
Multiplication<br />
1 £249.50<br />
2 Yes, her Nan will have to give her £35.80.<br />
3 £48.46<br />
Area<br />
1 e.g.<br />
2 £210<br />
3 £248<br />
4 e.g. 1 cm by 36 cm, perimeter 74 cm; 2 cm by 18 cm,<br />
perimeter 40 cm; 3 cm by 12 cm, perimeter 30 cm; 4 cm by<br />
9 cm, perimeter 26 cm; 6 cm by 6 cm, perimeter 24 cm<br />
5 £8<br />
Averages and range<br />
1 a Add 2 b the same c double<br />
d double e 1 2 3 4 5 8 19<br />
2 72<br />
3 <strong>The</strong> new mean is two larger.<br />
4<br />
English<br />
50<br />
Maths<br />
45<br />
Cumulative frequency<br />
40<br />
35<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
0 10 20 30 40 50 60 70 80 90 100<br />
Marks<br />
665<br />
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<strong>Answers</strong><br />
20 30 40 50 60 70 80 90 100<br />
Maths<br />
20 30 40 50 60<br />
English<br />
70 80 90 100<br />
<strong>The</strong> median for Maths (62) is larger than the Median for<br />
English (60).<br />
<strong>The</strong> Maths marks are more varied as <strong>The</strong> IQR is 20<br />
compared with the English IQR of 15.<br />
5 a May’s average hours of sunshine are higher than June<br />
so May had more hours of sunshine than June<br />
<strong>The</strong> number of hours of sunshine were more variable in<br />
June as the range was bigger.<br />
b i <strong>The</strong> mean and range take into account all of the data.<br />
ii <strong>The</strong> median and IQR are not affected by extreme<br />
values.<br />
Price comparisons<br />
1 Ahmed should use Cogas if he uses fewer than 3800 units<br />
per annum, otherwise he should use Ourgas.<br />
2 a Cable: C 30 5m; Broadband: C 6.5m<br />
b Broadband is cheaper for up to 20 months.<br />
3 a ACars: C 60 0.32x; BMotors: C 50 0.4x<br />
b ACars is cheaper for more than 125 miles a day.<br />
4 Quick Delivery for parcels up to 1.5 kg and Parcels Fly for<br />
parcels over 1.5 kg<br />
5 Pete’s Mix if more than 3.33 m 3 , otherwise Concrete Sue<br />
Intepreting and displaying data<br />
1<br />
Cumulative frequency<br />
100<br />
90<br />
80<br />
70<br />
60<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0<br />
0 10 20 30 40 50 60 70 80<br />
Weight (g)<br />
3 Take a random stratified sample.<br />
Stratified by school 9 from Avon, 10 from Moorside,<br />
14 Heaton, 12 Moortop, 15 Brambell<br />
Students must be chosen randomly (names in a hat)<br />
Or<br />
Take a systematic sample ___ 5720 students 95<br />
60<br />
Put numbers 1–95 in a hat and draw out a number.<br />
Go systematically through each school numbering all<br />
students and selecting the students with numbers divisible<br />
by the number drawn.<br />
Or<br />
Put all names in a hat and draw out 60 students – this<br />
sample may not contain students from every school.<br />
4 75<br />
Probability<br />
1 1_ .<br />
, 33% or 0. 3<br />
3<br />
2 When Mona has eaten one sweet there are 19 sweets left<br />
in the bag. <strong>The</strong>re are still x chocolates. So the probability of<br />
Sam eating a chocolate is __ x<br />
19 .<br />
3 <strong>The</strong> probability of the first sock picked being x, depends on<br />
the total number of socks in the drawer (i.e. the number of<br />
grey socks the number of black socks) and the number<br />
of black socks at the start. When one black sock has been<br />
removed, the number of black socks and the total number of<br />
socks will both be lower by one. <strong>The</strong>refore the probability of<br />
picking a black sock the second time will not be x.<br />
4 3_ , 0.375 or 37.5%<br />
8<br />
5 20%, 1_ or 0.2<br />
5<br />
6 0.1, __ 1 or 10%<br />
10<br />
7 0.625, 5_ or 62.5%<br />
8<br />
Trigonometry<br />
1 14 cm<br />
2 12.0 cm<br />
3 From corner of shed to top of roof at opposite end<br />
√ __________<br />
6 2 2 2 7 2 9.43 ft, so the bean poles will fit in the<br />
shed.<br />
Climbing Snowdon<br />
1 <strong>The</strong> 9 am train is cheaper by £17. (£35 compared to £52)<br />
2 Rashid: time 2.75 hours, distance 7 km,<br />
speed 2.55 km/h<br />
Chelsea: time 3 hours, distance 9 km,<br />
speed 3 km/h<br />
Rashid is not the faster walker.<br />
11 pebbles<br />
2 10 workers<br />
666<br />
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3 a<br />
Metres<br />
1400<br />
1200<br />
1000<br />
800<br />
600<br />
<strong>Answers</strong><br />
3 Suitable questions for a data collection sheet, for example:<br />
Are you male or female? Male Female<br />
How old are you?<br />
0–14 15–29 30–44 45–59 60–74<br />
75–89 90 or over<br />
How much do you spend on music each month?<br />
£0–4.99 £5–9.99 £10–14.99 £15–19.99<br />
£20 or more<br />
What kind of music do you buy most often?<br />
Pop Classical Jazz Folk Other<br />
400<br />
200<br />
0<br />
0 1000 2000 3000 4000<br />
Feet<br />
b Height of Snowdon 3560 0.3048 1085 m<br />
Ben Nevis is higher.<br />
Music sales<br />
1 Sales in £ millions:<br />
2006 2007 2008 2009<br />
Downloads 69 115 169 160<br />
CDs 134 135 98 101<br />
Total 203 250 267 261<br />
<strong>The</strong> total sales between 2006 and 2008 increase each year<br />
and then decrease slightly in 2009.<br />
CD sales stay approximately the same from 2006 to 2007<br />
and then decrease, whereas download sales increase<br />
significantly each year before steadying out in 2009.<br />
2 Various answers are possible, for example, two frequency<br />
polygons.<br />
CDs (millions)<br />
Downloads (millions)<br />
60<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0<br />
0 10 20 30 40 50 60 70 80 90<br />
Age (years)<br />
60<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0<br />
0 10 20 30 40 50 60 70 80 90<br />
Age (years)<br />
Communication<br />
1 Students’ comparisons of costs for different numbers of<br />
months. For more than 18 months, ‘pay as you go’ is<br />
cheaper, otherwise monthly contract is cheaper.<br />
2 860.16 seconds<br />
3 13 cm by 19 cm (285 ppi by 284 ppi)<br />
15 cm by 23 cm (247 ppi by 235 ppi)<br />
20 cm by 30 cm (185 ppi by 180 ppi)<br />
Ranji should print the photo at 13 cm by 19 cm.<br />
Energy efficiency<br />
1 100 mm: Space Combi (Economy roll £200, Easy Roll £175,<br />
Space Combi £40)<br />
150 mm: Space Blanket (medium) (Economy roll £300,<br />
Space Blanket (medium) £168)<br />
200 mm: Space Combi (Economy roll £400, Space Blanket<br />
(thick) £210, Space Combi £80)<br />
2 £18.66<br />
3 100 weeks<br />
Going on holiday<br />
1 155 points<br />
2 England (England €478.80, Malta €483)<br />
3 16:56<br />
All at sea<br />
1 12 664 m<br />
2<br />
65°<br />
3 12:29<br />
8000 m<br />
Chapter 17 <strong>Answers</strong><br />
17.1 Get Ready<br />
1 arc, mean<br />
a Start at square K, go 1 to the right, then 1 down and stop.<br />
<strong>The</strong>n go 2 up, and 1 to the left and stop. <strong>The</strong>n go 4 to the<br />
right, and 3 down and stop.<br />
50°<br />
667<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 667<br />
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<strong>Answers</strong><br />
b Start at square C, go 1 up, then 1 left and stop. <strong>The</strong>n go 2<br />
up and 1 to the right and stop. <strong>The</strong>n go 3 down and stop.<br />
<strong>The</strong>n go 1 to the left and 2 up and stop. <strong>The</strong>n go 3 to the<br />
right and 2 down and stop.<br />
c Start at square A, go 3 to the right and stop. <strong>The</strong>n go 1 up<br />
and then 1 down and stop.<br />
d Students' examples<br />
Exercise 17A<br />
1 a ( 5) 5 b<br />
2<br />
( c<br />
4) (0)<br />
4<br />
d (4) 0 e ( 2 f<br />
3) ( 2<br />
5)<br />
2 y<br />
6<br />
D<br />
5<br />
4<br />
3<br />
2<br />
1<br />
4 3 2 1 O 1 2 3 4 5 6 7 8 9<br />
1<br />
F<br />
2<br />
3<br />
4<br />
3 a y<br />
5<br />
b ( 5 3)<br />
4<br />
3<br />
2<br />
1<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
2<br />
4 a, b y<br />
5<br />
A<br />
4<br />
3<br />
2<br />
1<br />
C<br />
5 4 3 2 1 O<br />
1<br />
1 2 3 4 5<br />
c ( 2 4) d (<br />
2<br />
4)<br />
2<br />
3<br />
A<br />
4<br />
5<br />
A<br />
B<br />
B<br />
E<br />
x<br />
C<br />
x<br />
B<br />
x<br />
17.2 Get Ready<br />
A: x 4, B: y 3, C: y x, D: y x<br />
Exercise 17B<br />
1 a, b y<br />
6<br />
Q<br />
5<br />
4<br />
3<br />
2<br />
1<br />
R<br />
6 5 4 3 2 1 O 1 2 3 4 5 6<br />
1<br />
T<br />
2<br />
3<br />
4<br />
5<br />
6<br />
c Reflection in the line y 1<br />
2 a, b y<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
6 5 4 3 2 1 O 1 2 3 4 5 6<br />
1<br />
2<br />
3<br />
C<br />
4<br />
5<br />
6<br />
c Reflection in the line y x<br />
3 a y<br />
7<br />
Q<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
3<br />
4<br />
5<br />
6<br />
7<br />
B<br />
x 1<br />
7 6 5 4 3 2 1 O 1 2 3 4 5 6 7 x<br />
1<br />
y 1<br />
2<br />
b Reflection in the line x 1<br />
A<br />
P<br />
P<br />
R<br />
x<br />
x<br />
668<br />
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<strong>Answers</strong><br />
17.3 Get Ready<br />
1 a 9 b i 90° clockwise ii 180° iii 150° clockwise<br />
2 a 90° clockwise<br />
b 90° anticlockwise<br />
c 180°<br />
d 150° anticlockwise<br />
Exercise 17C<br />
1 y<br />
6<br />
5<br />
4<br />
D<br />
3<br />
2<br />
1<br />
6 5 4 3 2 1 O<br />
1<br />
1 2 3 4 5 6<br />
2<br />
B<br />
3<br />
4<br />
5<br />
6<br />
C<br />
2 y<br />
6<br />
5<br />
4<br />
S<br />
3<br />
2<br />
1<br />
6 5 4 3 2 1 O 1 2 3 4 5 6<br />
1<br />
Q<br />
2<br />
3<br />
R<br />
4<br />
5<br />
6<br />
3 a i 90° anticlockwise about the origin<br />
ii 180° about the origin<br />
iii 90° clockwise about the origin<br />
b 90° clockwise about the origin<br />
c 180° about the origin<br />
4 a i 180° about (3, 5)<br />
ii 90° clockwise about (2, 1)<br />
iii 180° about (0, 0)<br />
iv 90° anticlockwise about (0, 4)<br />
v 90° anticlockwise about (2, 2)<br />
b 90° clockwise rotation about (2, 8)<br />
c i Translation ( 6<br />
10) ii Translation ( 4 0)<br />
A<br />
P<br />
x<br />
x<br />
17.4 Get Ready<br />
1,2<br />
y<br />
3<br />
2<br />
1<br />
O<br />
1 2 3 x<br />
3 <strong>The</strong>y are both squares.<br />
<strong>The</strong>y have a common vertex at (0, 0).<br />
<strong>The</strong> second square is twice as large as the first square.<br />
Exercise 17D<br />
1 a 48 cm, 52 cm, 20 cm<br />
b <strong>The</strong> perimeter is also 4 times as long.<br />
2 a, b<br />
A<br />
B<br />
c 6<br />
3 a P is 4 cm by 2 cm, Q is 8 cm by 4 cm, R is 12 cm by 6 cm.<br />
b i 12 cm ii 24 cm iii 36 cm<br />
c i 8 cm 2 ii 32 cm 2 iii 72 cm 2<br />
d i 2, same as scale factor<br />
ii 3, same as scale factor<br />
e i 4, same as scale factor squared<br />
ii 9, same as scale factor squared<br />
f 96 cm<br />
Exercise 17E<br />
1 a<br />
C<br />
669<br />
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<strong>Answers</strong><br />
b<br />
2 a, b<br />
iii<br />
ii<br />
i<br />
y<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
C<br />
A<br />
Exercise 17F<br />
1 a, b<br />
y<br />
12<br />
11<br />
10<br />
9<br />
8<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
O<br />
F<br />
c Translation ( 9 4)<br />
d Translation ( 9<br />
4)<br />
G<br />
1 2 3 4 5 6 7 8 9 10 11 12<br />
H<br />
x<br />
109<br />
8 7 6 5 4 3 2 1 O<br />
1<br />
1 2 3 4 5<br />
2<br />
B<br />
3<br />
4<br />
5<br />
6<br />
7<br />
8<br />
c 6<br />
x<br />
2 a, b y<br />
6<br />
5<br />
4<br />
T<br />
3<br />
V<br />
2<br />
1<br />
6 5 4 3 2 1 O 1 2 3 4 5 6<br />
1<br />
U<br />
2<br />
3<br />
x<br />
3 a y<br />
5<br />
4<br />
3<br />
2<br />
P<br />
1<br />
5 4 3 2 1 O<br />
1<br />
1 2 3 4 5<br />
2<br />
3<br />
4<br />
5<br />
b Rotation 180° about (1, 2)<br />
x<br />
c Rotation 180° about (4, 3)<br />
3 a, b y<br />
4<br />
3<br />
2<br />
1<br />
2 1 O 1 2 3 4<br />
1<br />
2<br />
3<br />
4<br />
5<br />
U<br />
T<br />
V<br />
5 6<br />
x<br />
c Reflection in the x-axis<br />
4 Reflection in the line x 5<br />
5 Reflection in the x-axis<br />
670<br />
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<strong>Answers</strong><br />
Review exercise<br />
1<br />
4 y<br />
7<br />
6<br />
5<br />
4<br />
B<br />
3<br />
2<br />
1<br />
A<br />
C<br />
6 5 4 3 2 1 O<br />
1<br />
2<br />
3<br />
4<br />
5<br />
1 2 3 4 5 6 7<br />
x<br />
5 Students’ tile designs<br />
6 90° clockwise rotation about (–2, 3)<br />
2 a y<br />
8<br />
6<br />
4<br />
2<br />
7 y<br />
5<br />
4<br />
3<br />
2<br />
8 6 4 2 O 2 4 6 8<br />
2<br />
b Translation (<br />
3<br />
1)<br />
4<br />
6<br />
8<br />
x<br />
1<br />
5 4 3 2 1 O<br />
1<br />
B<br />
2<br />
3<br />
4<br />
5<br />
1 2 3 4 5<br />
A<br />
x<br />
3 a y<br />
5<br />
4<br />
A<br />
3<br />
2<br />
1<br />
5 4 3 2 1 O<br />
1<br />
2<br />
B<br />
3<br />
4<br />
5<br />
1 2 3 4 5<br />
x<br />
8 a Reflection in the line y x<br />
b<br />
y<br />
4<br />
C<br />
3<br />
A<br />
2<br />
B<br />
1<br />
4 3 2 1 O<br />
1<br />
2<br />
3<br />
4<br />
1 2 3 4<br />
x<br />
b 90° anticlockwise rotation about the origin<br />
671<br />
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<strong>Answers</strong><br />
9 a y<br />
6<br />
10<br />
6 5 4 3 2 1 O<br />
1<br />
b Translation (<br />
5<br />
4)<br />
y<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
5<br />
4<br />
3<br />
2<br />
1<br />
2<br />
3<br />
4<br />
5<br />
6<br />
1 2 3 4 5 6<br />
6 5 4 3 2 1 O<br />
1<br />
A<br />
1 2 3 4 5 6 7 8 9<br />
2<br />
3<br />
4<br />
5<br />
6<br />
11 180° rotation about (1, 0)<br />
12 180° rotation about the origin<br />
Chapter 18 <strong>Answers</strong><br />
18.1 Get Ready<br />
1 360<br />
2 90<br />
3 a 120 b 45 c 60<br />
Exercise 18A<br />
1<br />
Latte<br />
Coke<br />
Orange<br />
Chocolate<br />
Tea<br />
Black<br />
coffee<br />
P<br />
x<br />
x<br />
2 Chicken Cheese<br />
3<br />
Ham<br />
Prawn<br />
Motorbike<br />
Train<br />
Cycle<br />
Tuna<br />
BLT<br />
Walk<br />
Car<br />
Exercise 18B<br />
1 a Golf b Athletics c 45 d 30<br />
2<br />
Shop A<br />
Shop B<br />
Cappuccino<br />
Mocha<br />
Espresso<br />
18.3 Get Ready<br />
a 50, 54, 65, 72<br />
b 4.0, 4.3, 4.4, 4.6<br />
c 0.01, 0.1, 0.11, 0.12<br />
Exercise 18C<br />
Americano<br />
Latte<br />
Cappuccino<br />
Mocha<br />
Espresso<br />
Americano<br />
Latte<br />
1 a 36 b 28 c 47 d 18, 36 e 18<br />
2 a<br />
0 4 5 6 7 7 8 9 9 9 9<br />
1 0 2 4 5 7<br />
2 1 4 8<br />
3 0<br />
Key 2 | 1 stands for 21<br />
b 9 minutes c 9 minutes d 26 minutes<br />
e 7 minutes, 17 minutes f 10 minutes<br />
3 a<br />
5 2 6 9<br />
6 3 3 4 5 5 8 8 8 9<br />
7 2 4 4 4 4<br />
8 2 3 5 8<br />
9 2 4<br />
Key 7 | 2 stands for 72<br />
b 74 km c 69 km d 42 km<br />
e 64 km, 82 km f 18 km<br />
672<br />
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<strong>Answers</strong><br />
18.4 Get Ready<br />
a B occurs more frequently than A, which occurs more<br />
frequently than C.<br />
b <strong>The</strong> red category accounts for a higher proportion of the<br />
total than the green or blue categories. Red: 50%, green and<br />
blue: 25% each.<br />
Exercise 18D<br />
1 a 30°C b 33°C c G d C and F e A<br />
2 a Food b Pension c 25%<br />
3 a 70 g b 10 g c Fruitbix<br />
4 a Saturday b Thursday c 40<br />
18.5 Get Ready<br />
a 3 b 16 c 25<br />
Exercise 18E<br />
1<br />
14<br />
Frequency<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
0<br />
0 to 2 3 to 5 6 to 8 9 to 11 12 to 14<br />
Number of games<br />
2 a 135 w 140 b 140 w 145<br />
c<br />
16<br />
14<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
0<br />
125 130 135 140 145 150<br />
Wingspan (cm)<br />
Frequency<br />
3 a 139 w 141 b 137 w 139<br />
c<br />
16<br />
14<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
0<br />
135 137 139 141 143 145<br />
Weight (g)<br />
Frequency<br />
18.6 Get Ready<br />
a 5 b 17.5 c 115.5<br />
Exercise 18F<br />
1<br />
Frequency<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
2 3 4 5 6 7 8<br />
Number of peas<br />
2 a 70 d 80<br />
b, c<br />
3<br />
Frequency<br />
Frequency<br />
16<br />
14<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
18<br />
16<br />
14<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
0<br />
60 70 80 90 100<br />
Noise level (decibels)<br />
0<br />
24 25 26 27 28 29<br />
Trout length (cm)<br />
4 Girls, because their mode is 5 minutes and the boys’ mode<br />
is 9 minutes.<br />
Exercise 18G<br />
1 a Lifetime<br />
(l hours)<br />
Frequency<br />
Class<br />
width<br />
Frequency<br />
density<br />
10 l 15 4 5 0.8<br />
15 l 20 10 5 2<br />
20 l 25 20 5 4<br />
25 l 30 15 5 3<br />
30 l 40 6 10 0.6<br />
673<br />
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<strong>Answers</strong><br />
2<br />
b<br />
Frequency density<br />
Frequency density<br />
25<br />
4.5<br />
4<br />
3.5<br />
3<br />
2.5<br />
2<br />
1.5<br />
1<br />
0.5<br />
0<br />
10 15 20 25 30 35 40<br />
Lifetime (hours)<br />
3.5<br />
3<br />
2.5<br />
2<br />
1.5<br />
1<br />
0.5<br />
0<br />
0<br />
5 10 15 20 25 30 35 40<br />
Distance (kilometres)<br />
3 a Age (y years) Frequency<br />
0 y 5 10<br />
5 y 10 28<br />
10 y 20 49<br />
20 y 40 48<br />
40 y 70 60<br />
Exercise 18H<br />
1 a Cumulative frequency: 3, 10, 20, 35, 43, 48, 50<br />
b<br />
Cumulative frequency<br />
60<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0<br />
0 5 10 15 20 25 30 35 40<br />
Age (years)<br />
2 a 11 b 19 c 33<br />
3 a i 22 ii 74<br />
b 110<br />
c 18%<br />
18.9 Get Ready<br />
a 9 and 12<br />
b 18 and 20<br />
Exercise 18I<br />
1 a 42 b 33, 50 c 17 d 70<br />
2 a £6000 b £4000, £7500 c £3500<br />
3 a Median £242 000, Q 1 £222 000, Q 3 £256 000<br />
b Range £120 000, interquartile range £34 000<br />
18.10 Get Ready<br />
Median 15<br />
Lower quartile 8<br />
Upper quartile 25<br />
Interquartile range 17<br />
Exercise 18J<br />
1<br />
Frequency density<br />
b 101<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
0<br />
0 10 20 30 40 50 60 70 80<br />
Age (years)<br />
2<br />
4 5 6<br />
Height (m)<br />
29 30 31 32 33 34 35 36 37 38 39 40 41<br />
Height (m)<br />
3 a Male: min 10, Q 1 20, Q 2 40, Q 3 50, max 80<br />
Female: min 10, Q 1 30, Q 2 50, Q 3 60, max 80<br />
b<br />
Male<br />
Female<br />
0 10 20 30 40 50 60 70 80 90<br />
Age (years)<br />
674<br />
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<strong>Answers</strong><br />
<strong>The</strong> female members are older on average (higher<br />
median). <strong>The</strong> interquartile range is the same for males<br />
and females, but the range is slightly greater for females<br />
so their ages vary slightly more.<br />
Review exercise<br />
1<br />
2<br />
Art<br />
Music<br />
108°<br />
72°<br />
60°<br />
120° French<br />
Tea<br />
History<br />
Hot<br />
chocolate<br />
120°<br />
80°<br />
60°<br />
100°<br />
Coffee<br />
Soup<br />
3 a 14 b 5<br />
c<br />
16<br />
Number of students<br />
14<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
0<br />
d Tuesday<br />
4 a 4 6 8<br />
Monday<br />
5 1 2 8<br />
6 0 3 4 6 8<br />
7 4 7 8 9<br />
8 7<br />
Tuesday Wednesday Thursday<br />
Days of the week<br />
Key 5 | 1 means 51 kg<br />
b 5<br />
c 87 46 41 kg<br />
5 30 mm<br />
6<br />
30<br />
Frequency<br />
20<br />
10<br />
0<br />
100 110 120 130 140 150<br />
Weight (w grams)<br />
Key:<br />
Boys<br />
Girls<br />
Friday<br />
7<br />
Frequency<br />
20<br />
15<br />
10<br />
5<br />
0<br />
0 10 20 30 40 50<br />
Science mark<br />
8 James. <strong>The</strong> angle for the combined proportion must be<br />
between the Year 9 and Year 10 angles.<br />
9 On average, the prices are lower at Peter’s garage than at<br />
John’s garage, as the median is lower. <strong>The</strong> range and<br />
interquartile range are both smaller for Peter’s garage<br />
so the spread is less than for John’s garage. Both the<br />
cheapest and the most expensive cars come from John’s<br />
garage.<br />
10 a 88 people b 38 years c 57 21 36 years<br />
11 a<br />
1.30 1.40 1.50 1.60<br />
1.70 1.80 1.90<br />
Girls’ height (m)<br />
b On average, the girls are taller than the boys, as the<br />
median is higher, but the boys' heights are more<br />
variable as the range is larger. <strong>The</strong> interquartile ranges<br />
are the same so the variation in the middle of each<br />
group is similar.<br />
12 From a cumulative frequency chart, the median for the men<br />
is £240. On average, the men spent more than the women.<br />
13 a 23 kg is the value of Q 3 . <strong>The</strong> heaviest bag weighs 29 kg.<br />
b 17 kg c 13 kg d 60 bags<br />
14 a 21 b 10<br />
c Most of the high and low scores are scored by the<br />
boys. More of the girls scored an average mark.<br />
15<br />
Frequency density<br />
4<br />
3<br />
2<br />
1<br />
0<br />
40 50 60 70 80 90 100 110<br />
16 a<br />
Time (t minutes)<br />
0 10 20 30<br />
Minutes<br />
40 50 60<br />
b <strong>The</strong> delays were greater on Saturday, as the median<br />
and the quartiles are all higher. <strong>The</strong>re was also more<br />
variation in the delays on Saturday, since both the<br />
range and the interquartile range are larger.<br />
675<br />
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<strong>Answers</strong><br />
17 a<br />
100<br />
b<br />
5<br />
Cumulative frequency<br />
80<br />
60<br />
40<br />
20<br />
b 68 mph<br />
0<br />
40 50 60 70 80 90 100<br />
Speed (s mph)<br />
c 76 61 15 mph<br />
Frequency density<br />
4<br />
3<br />
2<br />
1<br />
0<br />
0 10 20 30 40<br />
Weight (w kg)<br />
c 57.5 d 35<br />
18 a<br />
Distance (d km) Frequency<br />
0 d 5 15<br />
5 d 10 20<br />
10 d 20 25<br />
20 d 40 20<br />
40 d 60 10<br />
20 20 batteries<br />
Chapter 19 <strong>Answers</strong><br />
19.1 Get Ready<br />
1 a 2.8 b 0.4 c 0.8 d 2.6<br />
Exercise 19A<br />
1 a<br />
b<br />
4<br />
b<br />
5 4 3 2 1 0 1 2 3 4 5<br />
5 4 3 2 1 0 1 2 3 4 5<br />
Frequency density<br />
3<br />
2<br />
c<br />
d<br />
5 4 3 2 1 0 1 2 3 4 5<br />
1<br />
5 4 3 2 1 0 1 2 3 4 5<br />
0<br />
0 10 20 30 40 50 60<br />
Distance (d km)<br />
e<br />
5 4 3 2 1 0 1 2 3 4 5<br />
19 a<br />
Weight (w kg)<br />
Frequency<br />
Frequency<br />
density<br />
0 w 5 20 4<br />
5 w 15 30 3<br />
15 w 25 15 1.5<br />
25 w 35 10 1<br />
35 w 40 5 1<br />
2 a x 4 b x 1 c x 5 and x 2<br />
d x 0 and x 3<br />
e x 3 and x 5<br />
f x 5 and x 1<br />
19.2 Get Ready<br />
1 x 10<br />
2 x 1_<br />
2<br />
3<br />
4<br />
1 2 3 4 5 6 7 8 9 10<br />
5 6 7 8 9 10 11 12 13 14 15<br />
676<br />
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<strong>Answers</strong><br />
Exercise 19B<br />
1 a x 4<br />
2<br />
y<br />
5<br />
4<br />
y 3x 4<br />
5 4 3 2 1 0 1 2 3<br />
4 5<br />
3<br />
2<br />
b x 1<br />
1<br />
5 4 3 2 1 0 1 2 3 4 5<br />
c x 2<br />
5 4 3 2 1<br />
O<br />
1<br />
2<br />
3<br />
1<br />
2 3 4 5<br />
x<br />
5 4 3 2 1 0 1 2 3 4 5<br />
d x 1.6<br />
4<br />
5<br />
5 4 3 2 1 0 1 2 3 4 5<br />
2 a x 4.5 b x 4 c x 2.5 d x 6.5<br />
3 a x 3.25 b x 23 c x 6<br />
11 d x __ 1<br />
19<br />
19.3 Get Ready<br />
1 x 4 2 x 4 3 x 2 4 x 3<br />
Exercise 19C<br />
1 a 1, 0, 1, 2, 3, 4, 5<br />
b 4, 3, 2, 1, 0, 1<br />
c 1, 2, 3<br />
d 5, 4, 3, 2, 1, 0, 1, 2, 3, 4<br />
2 a 3, 2, 1, 0, 1, 2, 3<br />
b 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 7<br />
c 0, 1, 2, 3, 4<br />
d 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9<br />
3 a 2, 1, 0, 1, 2, 3<br />
b 1, 0, 1, 2, 3, 4<br />
c 1, 0, 1, 2, 3, 4<br />
d 7, 6, 5, 4, 3, 2, 1, 0, 1, 2, 3, 4<br />
4 a 2, 1, 0, 1, 2, 3, 4, 5, 6<br />
b 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 7<br />
c 0, 1, 2, 3<br />
d 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10<br />
19.4 Get Ready<br />
1<br />
y<br />
5<br />
5 4 3 2 1<br />
O<br />
1<br />
4<br />
3<br />
2<br />
1<br />
2<br />
3<br />
4<br />
5<br />
1<br />
y 4x 1<br />
2 3 4 5<br />
x<br />
3<br />
y<br />
2y 3x 4<br />
5<br />
4<br />
3<br />
2<br />
1<br />
5 4 3 2 1<br />
O<br />
1 2 3 4 5<br />
x<br />
1<br />
2<br />
3<br />
4<br />
5<br />
Exercise 19D<br />
1 (1, 1), (1, 0), (1, 1), (0, 0), (0, 1), (1, 1)<br />
y<br />
4<br />
3<br />
2<br />
1<br />
4 3 2 1 O 1 2 3 4 5 x<br />
1<br />
2<br />
3<br />
4<br />
5<br />
677<br />
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<strong>Answers</strong><br />
2 a<br />
y<br />
6<br />
d<br />
y<br />
6<br />
4<br />
4<br />
2<br />
2<br />
6<br />
4<br />
2<br />
O<br />
2 4 6<br />
x<br />
6<br />
4<br />
2<br />
O<br />
2 4 6<br />
x<br />
2<br />
2<br />
4<br />
4<br />
6<br />
6<br />
b<br />
y<br />
6<br />
3 a<br />
y<br />
6<br />
4<br />
4<br />
2<br />
2<br />
6<br />
4<br />
2<br />
O<br />
2 4 6<br />
x<br />
6<br />
4<br />
2<br />
O<br />
2 4 6<br />
x<br />
2<br />
2<br />
4<br />
4<br />
6<br />
6<br />
c<br />
y<br />
6<br />
b<br />
y<br />
6<br />
4<br />
4<br />
2<br />
2<br />
6<br />
4<br />
2<br />
O<br />
2 4 6<br />
x<br />
6<br />
4<br />
2<br />
O<br />
2 4 6<br />
x<br />
2<br />
2<br />
4<br />
4<br />
6<br />
6<br />
678<br />
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<strong>Answers</strong><br />
c<br />
y<br />
6<br />
4<br />
2<br />
Exercise 19F<br />
1 a C 50d 90 b €790<br />
2 P 5x 3y z<br />
45m 75f<br />
3 T _________ _______ 3m 5f<br />
60 4<br />
4 P 4x 4y<br />
5 a T 2a 5c b P 2a 3c<br />
d<br />
6<br />
6<br />
4<br />
4<br />
2<br />
2<br />
O<br />
2<br />
4<br />
6<br />
y<br />
6<br />
2<br />
4<br />
6<br />
4 a y 3, y 2x 3, x y 1<br />
b y 3, y 2x 3, x y 1<br />
c (2, 2), (1, 2) and (1, 1)<br />
5 a y 2, x 3, y 1_ x 3, y x<br />
2<br />
b y 2, x 3, y 1_ x 3, y x<br />
2<br />
c 1<br />
19.5 Get Ready<br />
1 a 5347.76 b<br />
Exercise 19E<br />
8_ 2_<br />
, or 2<br />
3 3<br />
1 a 120 b 25<br />
2 a 65 b 5<br />
3 a 1570 b 120.576<br />
4 a 120 miles b 8 m/s<br />
5 a 5 hours 5 minutes b 18 lb<br />
6 a 12 b 9<br />
19.6 Get Ready<br />
a 3200 b 9<br />
4<br />
2<br />
O<br />
2 4 6<br />
2 4 6<br />
x<br />
x<br />
19.7 Get Ready<br />
1 60 miles 2 1.8 10 17<br />
Exercise 19G<br />
1 x _____ y 3<br />
5<br />
3 a _____ v u<br />
t<br />
5 m _____ 4 E<br />
3<br />
2 d _____ c 2<br />
5<br />
4 x P y _____<br />
5y<br />
6 g ______ f 30<br />
3<br />
7 x 7T 2 8 n ________ 2Y 3m<br />
3<br />
3W 2y<br />
9 p ________<br />
2y<br />
10 w 4 3A<br />
19.8 Get Ready<br />
1 u v at 2 R V __<br />
I<br />
Exercise 19H<br />
__<br />
1 R √<br />
__ A<br />
<br />
3 u √ ________<br />
v 2 2as<br />
5 x √ _______<br />
_______ 75 y 2<br />
50<br />
7 m _____ 1<br />
T 3<br />
9 c _____ a 3<br />
b 7<br />
Review exercise<br />
3 m E __<br />
c 2<br />
2 x P 2 y<br />
4 g 2s __<br />
T 2<br />
6 g _____ f 4<br />
4<br />
8 p ______ q 12<br />
q 4<br />
10 T ________ 7<br />
2W 2 3<br />
1 9<br />
2 a b 3a b c a 5<br />
3 a £130 b C 90 0.5m<br />
4 0.6<br />
5 a 8 b p ______ S 3q<br />
4<br />
6 a 1 x 4 b 1 x 5 c x 2<br />
7 a<br />
b<br />
c<br />
d<br />
5 4 3 2 1 0 1 2 3 4 5<br />
5 4 3 2 1 0 1 2 3 4 5<br />
5 4 3 2 1 0 1 2 3 4 5<br />
5 4 3 2 1 0 1 2 3 4 5<br />
8 3, 2, 1, 0, 1<br />
679<br />
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<strong>Answers</strong><br />
9 a t 5.5 b 5<br />
10 3, 2, 1, 0, 1, 2<br />
11 p 3<br />
12 0 x 4<br />
13 a L x (x 4) 2(x 4) x x 4 2x 8<br />
4x 12<br />
b 4x 12 50 c 0 x 9.5<br />
14<br />
y<br />
6<br />
6<br />
4<br />
2<br />
4<br />
2<br />
O<br />
2<br />
4<br />
R<br />
x y 6<br />
2 4 6 8<br />
x<br />
Chapter 20 <strong>Answers</strong><br />
20.1 Get Ready<br />
1 a 144 b 54.76<br />
2 a 1681 b 276.93<br />
3 a 225 b 102.55<br />
4 a 25 b 12<br />
5 a 6.44 b 8.91<br />
Exercise 20A<br />
1 a 13 cm b 10 cm c 10.4 cm d 11.6 cm<br />
2 a 12.6 cm b 11.7 cm c 14.4 cm d 20.8 cm<br />
Exercise 20B<br />
1 a 7 cm b 35 cm c 12.3 cm d 8.03 cm<br />
2 a 15.2 cm b 5.77 cm<br />
c i D<br />
10.1 cm<br />
6<br />
10<br />
15 a __<br />
7 b u _____ vf<br />
v f<br />
4y 15<br />
16 x _______<br />
5 3y<br />
17 a 24.8 b r ______ P 2a<br />
2<br />
18 a Any two of: (1, 1), (1, 2), (2, 1)<br />
b y<br />
x 0 y 3x<br />
8<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
4x 3y 12<br />
y 0<br />
0<br />
0 1 2 3 4 5 6 7 8<br />
x<br />
19 a x 2, y 3, 2x 3y 20<br />
b y<br />
x 2<br />
8<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
0<br />
0 1 2 3 4 5 6 7 8<br />
y 3<br />
2x 3y 20<br />
x<br />
E<br />
ii 6.42 cm<br />
20.2 Get Ready<br />
7.8 cm<br />
<strong>The</strong> rounded lengths are 21 cm and 30 cm. <strong>The</strong> diagonal is<br />
approximately 37 cm.<br />
Exercise 20C<br />
1 a 15.0 m b 6.92 cm c 18.7 cm<br />
2 3.47 m<br />
3 52.4 cm 2<br />
4 a 3.20 m<br />
b i 4.33 m ii 2.33 m<br />
c 8.66 m<br />
5 Triangles 1, 2, 4 and 6 are right-angled triangles.<br />
6 2.85 cm<br />
7 a 17 inches<br />
b Height 18 inches, width 32 inches<br />
20.3 Get Ready<br />
a 26 b 19.3 c 10.3<br />
Exercise 20D<br />
1 a 10 b 26 c √ ___<br />
212 14.6<br />
d √ ___<br />
424 20.6 e 29 f √ ___<br />
117 10.8<br />
2 a i 5 ii √ __<br />
50 7.07 iii 5<br />
b 5 2 5 2 50, so triangle is right-angled at A.<br />
3 a 13<br />
b B, C, E lie on the circle.<br />
20.4 Get Ready<br />
1 a p b r c q<br />
F<br />
680<br />
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<strong>Answers</strong><br />
2 a e b f c d<br />
3 a AC b BC c AB<br />
Exercise 20E<br />
1 a 0.3420 b 0.9542 c 0.5 d 0.9461<br />
e 1 f 15.8945 g 0.7408 h 0.0699<br />
i 0.7965 j 0.2538 k 0.3739 l 0.0471<br />
2 a 53.1 b 25.5 c 60 d 43.8<br />
e 58.4 f 63.8 g 2.7 h 60<br />
i 45<br />
Exercise 20F<br />
1 a sine b cosine c tangent d cosine<br />
Exercise 20G<br />
1 a 37.7° b 46.2° c 19.7° d 40.1°<br />
e 47.1° f 43.6°<br />
2 a 36.3° b 38.9° c 32.3°<br />
3 a 41.0° b 57.2° c 98°<br />
20.5 Get Ready<br />
1 a<br />
N<br />
Review exercise<br />
1 6.36 cm<br />
2 6.71 cm<br />
3 230 km<br />
4 19.4 cm<br />
5 20.6°<br />
6 a 51.3° b 10.5 cm<br />
7 21.7 m<br />
8 033°<br />
9 116 cm<br />
10 a Alan<br />
b 5 1_ seconds. Alan’s time _______ 60 80<br />
28 seconds,<br />
3 5<br />
Bhavana’s time _________<br />
√________ 60 2 80 2<br />
33 1_<br />
3<br />
3 seconds<br />
11 a<br />
b<br />
10 x<br />
x 2 x 2 10 2 , so x 7.07 cm<br />
x<br />
55°<br />
20 km<br />
12<br />
1<br />
x 10 cm<br />
5 2.24 m<br />
X<br />
2<br />
b<br />
2 cosine<br />
8 m<br />
3 m<br />
Exercise 20H<br />
1 a 5.47 cm b 17.1 cm c 11.6 cm<br />
d 26.1 cm e 10.4 cm f 11.3 cm<br />
2 a 18.1 cm b 13.4 m c 10.8 cm<br />
3 a i 9.96 cm ii 8.36 cm<br />
b 5.30 cm c 13.7 cm d 68 cm 2<br />
Exercise 20I<br />
1 a i 1.45 m ii 5.44 m iii 2.54 m<br />
b 65.0°<br />
2 a 16.8 m b 64.5° c 24.5°<br />
3 a 46.9 m b 88.3 m<br />
4 a 2.87 cm b 16.5°<br />
5 a i 13.0 km ii 10.9 km<br />
b i 7.73 km ii 23.8 km<br />
c i 20.7 km ii 34.7 km<br />
d 40.4 km, 059.2°<br />
6 a 3.84 cm b 16.8 cm c 43 cm 2<br />
a Area 4 2.24 8.96 m 2 , so he needs to buy two<br />
rolls of felt.<br />
b Two rolls of felt cost £24.00, two tins of adhesive cost<br />
£13.98, so total cost £37.98<br />
13 No. It depends on the diagonal of the desk:<br />
d 2 2.3 2 1.6 2 , d 2.80 m, but the room is only 2.75 m<br />
wide.<br />
Chapter 21 <strong>Answers</strong><br />
21.1 Get Ready<br />
1<br />
y<br />
5<br />
4<br />
3<br />
2<br />
1<br />
3 2 1<br />
O<br />
1<br />
2<br />
3<br />
1<br />
y 2x 3<br />
2 3<br />
2 a 4 b 4<br />
3 a 2 b 18<br />
x<br />
681<br />
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<strong>Answers</strong><br />
Exercise 21A<br />
1 a<br />
x 3 2 1 0 1 2 3<br />
y 6 1 2 3 2 1 6<br />
b<br />
y<br />
20<br />
18<br />
16<br />
b<br />
y<br />
8<br />
6<br />
y x 2 3<br />
14<br />
12<br />
10<br />
8<br />
6<br />
y 2x 2 2<br />
4<br />
4<br />
2<br />
2<br />
4 2 O 2 4<br />
x<br />
2<br />
4<br />
c x 0 d (0, 3)<br />
2 a<br />
x 3 2 1 0 1 2 3<br />
y 5 0 3 4 3 0 5<br />
4 2<br />
O<br />
2 4<br />
x<br />
c i y 6.5 ii x 2.1 and x 2.1<br />
4 a y<br />
12<br />
x 2<br />
10<br />
8<br />
6<br />
4<br />
2<br />
y x 2 4x 1<br />
2<br />
O<br />
2 4 6<br />
x<br />
2<br />
4<br />
6<br />
b<br />
y<br />
6<br />
4<br />
i x 4.2 and x 0.2 ii x 2<br />
b y<br />
x 1<br />
12<br />
10<br />
2<br />
8<br />
6<br />
4 2 O 2<br />
2<br />
4<br />
x<br />
y 4 x 2<br />
4<br />
y 2x 2 4x 3<br />
2<br />
2<br />
O<br />
2 4<br />
x<br />
2<br />
4<br />
4<br />
6<br />
6<br />
c (0, 4) d x 2 and x 2<br />
3 a<br />
x 3 2 1 0 1 2 3<br />
y 20 10 4 2 4 10 20<br />
i x 2.6 and x 0.6 ii x 1<br />
c<br />
x 2<br />
y<br />
20<br />
15<br />
10<br />
5 y (x 2) 2<br />
6 4 2<br />
O<br />
2<br />
x<br />
5<br />
i touches the x-axis at 2<br />
ii x 2<br />
682<br />
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<strong>Answers</strong><br />
d<br />
y<br />
10<br />
5<br />
2<br />
O<br />
2 4<br />
5<br />
10<br />
15<br />
20<br />
x 0.75<br />
y 5 3x 2x 2<br />
i x 2.5 and x 1 ii x 0.75<br />
Exercise 21B<br />
1 a x 0 and x 3 b x 1 and x 4<br />
c x 2.8 and x 1.3 d x 3.6 and x 1.6<br />
2 a x 0.4 and x 2.6 b x 0.4 and x 2.6<br />
c x 3.1 and x 1.6 d x 3.2 and x 1.2<br />
3 a<br />
x 2 1 0 1 2 3 4<br />
y 7 2 1 2 1 2 7<br />
b<br />
y 1 x<br />
y<br />
2<br />
x<br />
y 1 2x x 2<br />
Exercise 21C<br />
1 a<br />
x 3 2 1 0 1 2 3<br />
y 25 6 1 2 3 10 29<br />
b<br />
y<br />
30<br />
25<br />
20<br />
15<br />
10<br />
y x 3 2<br />
5<br />
3 2 1 O 1 2 3 x<br />
5<br />
10<br />
15<br />
20<br />
25<br />
30<br />
c y 17.6<br />
2<br />
O<br />
2<br />
2<br />
4<br />
x<br />
2 a<br />
x 4 3 2 1 0 1 2 3 4<br />
y 28 0 10 8 0 8 10 0 28<br />
4<br />
6<br />
8<br />
c x 0 and x 3<br />
4 a<br />
x 3 2 1 0 1 2 3<br />
y 32 16 6 2 4 12 26<br />
b<br />
y 2x 4<br />
y<br />
30<br />
25<br />
20<br />
15<br />
10<br />
2 O 2<br />
c x 1.5 and x 0.5<br />
21.2 Get Ready<br />
5<br />
y 3x 2 x 2<br />
1 1, 8, 27, 64, 125<br />
2 a 1 000 000 b 1000<br />
x<br />
b<br />
y<br />
30<br />
y x 3 9x<br />
25<br />
20<br />
15<br />
10<br />
5<br />
4 2 O 2 4 x<br />
5<br />
10<br />
15<br />
20<br />
25<br />
30<br />
c x 3, x 0 and x 3<br />
3 a<br />
x 3 2 1 0 1 2 3 4<br />
y 45 4 7 0 13 20 9 32<br />
683<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 683<br />
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<strong>Answers</strong><br />
b<br />
y<br />
50<br />
40<br />
30<br />
20<br />
10<br />
y 12x 3x 2 2x 3<br />
3 a y<br />
50<br />
40<br />
30<br />
20<br />
10<br />
y 12<br />
(x 1)<br />
2 O 2 4<br />
y 2x 1 10<br />
20<br />
30<br />
c x 1.5, x 0.1 and x 3.1<br />
4 i C ii A iii D iv B<br />
21.3 Get Ready<br />
1 a<br />
1_<br />
b 4 c 0.4 d 2.5<br />
4<br />
2 As the value of x gets bigger, the value of __ 1 gets smaller.<br />
x<br />
Exercise 21D<br />
1 a<br />
b<br />
c<br />
x 0.2 0.4 0.5 1 2 4 5 10 20<br />
y 25 12.5 10 5 2.5 1.25 1 0.5 0.25<br />
x 20 10 5 4 2 1 0.5 0.4 0.2<br />
y 0.25 0.5 1 1.25 2.5 5 10 12.5 25<br />
y<br />
25<br />
20<br />
15<br />
10<br />
5<br />
y x<br />
5<br />
20 1510 5 O<br />
5<br />
5 10 15 20<br />
10<br />
15<br />
20<br />
25<br />
x<br />
x<br />
4<br />
b x 1<br />
2 O 2<br />
10<br />
20<br />
30<br />
40<br />
50<br />
21.4 Get Ready<br />
1 a 81 b 1 c<br />
1_<br />
9<br />
2 a x 4 b x 2 c x 3<br />
Exercise 21E<br />
1 a<br />
b<br />
x 3 2 1 0 1 2 3<br />
y 0.04 0.111 0.33 1 3 9 27<br />
y<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
y 3 x<br />
3 2 1<br />
O<br />
1 2 3<br />
c i 5.2 ii 2.5<br />
2 A is y ( 1_<br />
2 ) x , B is y 3 x , C is y 5 x , D is y 2 x<br />
3 a 10 b 320 c 17 minutes<br />
4 p 0.625, q 16<br />
x<br />
x<br />
2 y<br />
10<br />
8<br />
6<br />
4<br />
2 y x<br />
2<br />
10 8 6 4 2 O 2 4 6 8 10<br />
2<br />
4<br />
6<br />
8<br />
10<br />
x<br />
21.5 Get Ready<br />
1 a 4.6 b 2.2 c 1.5<br />
2 When x 1, x __ 1 x 1 __ 1 1 2<br />
3 a 2 b 2<br />
Exercise 21F<br />
1 a 1 and 2 b 0 and 1 c 0 and 1, 1 and 0, 4 and 5<br />
d 2 and 3<br />
2 a 1.7 b 1.3 c 4.8 and 0.2<br />
3 a 3.04 b 2.17 c 4.72<br />
4 a x(x 2)(x 2) x 3 4x b x 8.6<br />
c 10.6 cm, 6.6 cm, 8.6 cm<br />
684<br />
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<strong>Answers</strong><br />
Review exercise<br />
1 a<br />
b<br />
2 a<br />
y<br />
450<br />
400<br />
350<br />
300<br />
250<br />
200<br />
150<br />
100<br />
50<br />
t 0 2 4 6 8 10<br />
s 0 49 116 201 304 425<br />
O<br />
c i 80.25 m<br />
b<br />
3 a<br />
1 2 3 4 5 6 7 8 9 10<br />
ii 9.6 seconds<br />
y 2.25x 2 20x<br />
x 4 3 2 1 0 1 2<br />
y 8 3 0 1 0 3 8<br />
y x 2 2x<br />
x 1<br />
4 2<br />
O<br />
2<br />
y<br />
10<br />
8<br />
6<br />
4<br />
2<br />
c x 1<br />
d i y 1.25 ii y 1.6 and y 3.6<br />
b<br />
x 3 2 1 0 1 2 3<br />
y 10 4 0 2 2 0 4<br />
4<br />
2<br />
2<br />
O<br />
2<br />
2<br />
4<br />
6<br />
8<br />
10<br />
y<br />
y 2 x x 2<br />
c i x 1 and x 2 ii 2.8 and 1.8<br />
d (0.5, 2.25)<br />
4 a x 2 3x 2 x 2<br />
x 2 3x 2 x 2 0<br />
x 2 4x 0<br />
b x 0 and x 4<br />
c y 2 x<br />
x<br />
x<br />
x<br />
5 a When x 0.5, x 2 2 __<br />
x 3 0.75<br />
When x 1, x 2 __ 2 x 3 2<br />
So there must be a solution to x 2 __ 2 x 3 0<br />
between x 0.5 and x 1.<br />
b 0.60<br />
6 a<br />
x 2 1 0 1 2 3 4<br />
b<br />
y 8 1 0 5 8 3 16<br />
y<br />
20<br />
15<br />
10<br />
5<br />
2<br />
O<br />
2 4<br />
5<br />
10<br />
x<br />
y x 3 2x 2 4x<br />
c i x 0, x 3.2 and x 1.2<br />
ii x 1.8, x 1 and x 2.8<br />
7 a<br />
x 3 2 1 0.5 0.1 0.1 1 2 3<br />
8 a<br />
b<br />
y 3.7 4 5 7 23 17 1 2 2.3<br />
c x 0, y 3<br />
b, c<br />
y<br />
25<br />
20<br />
15<br />
10<br />
5<br />
x 0<br />
2<br />
O<br />
2<br />
5<br />
2<br />
y 3 <br />
10<br />
x<br />
15<br />
20<br />
y 3<br />
x 0.5 1 2 3 4<br />
y 8 4 2 1.3 1<br />
y<br />
8<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
d x 2<br />
1<br />
y 4 x<br />
0<br />
0 1 2 3 4<br />
x<br />
x<br />
685<br />
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<strong>Answers</strong><br />
9 a<br />
12<br />
11<br />
10<br />
9<br />
8<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
O 0.5 1 1.5 2 2.5 3<br />
b 1.5 seconds<br />
c 2.86 seconds<br />
10 a<br />
24<br />
22<br />
20<br />
18<br />
16<br />
14<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
O 10 20 30 40 50 60 70 80<br />
b i 22 metres<br />
ii 9 metres and 71 metres<br />
iii 82 metres<br />
11 a y<br />
40<br />
30<br />
20<br />
10<br />
0<br />
0 1 2 3 4 5 x<br />
b 3.2 cm<br />
12 7.62 cm<br />
13 i C ii D iii A iv E v B<br />
14 k 0.25<br />
Chapter 22 <strong>Answers</strong><br />
22.1 Get Ready<br />
1 a x 1.5 b y 4<br />
2 a 4 b 21<br />
y x 2 3x<br />
Exercise 22A<br />
1 x 4, y 1 2 x 5, y 3<br />
3 x 1, y 2 4 x 2, y 1<br />
5 x 1, y 4 6 x 1, y 2<br />
7 x 1, y 1 8 x 2, y 1<br />
9 x 0.5, y 2 10 x 0.5, y 4<br />
11 x 3, y 1 12 x 2, y 0.5<br />
13 x 3, y 5 14 x 1, y 3<br />
15 x 0.5, y 1<br />
22.2 Get Ready<br />
1 x 2, y 3<br />
2 x 1, y 2<br />
3 x 3, y 1<br />
Exercise 22B<br />
1 7, 12<br />
2 £18.50<br />
3 £8.80<br />
4 Adult £4.50, child £3<br />
5 14 g<br />
6 a 4a 3b 1 or 4a 3b 1<br />
2a 3 5 b or 2a b 8<br />
b a 2.5 cm, b 3 cm<br />
7 Ann £9/day, Mary £12/day<br />
8 x 3, y 2<br />
22.3 Get Ready<br />
1 4a 3b 4<br />
3a 24 3b<br />
2 a 4, b 4<br />
3 56<br />
Exercise 22C<br />
1 a B y 2x, A x y 3, C x 2y 3<br />
b i x 1, y 2 ii x 3, y 0 iii x 1, y 2<br />
2 a x 2, y 0 b x 2.625, y 2.25 c x 2, y 8<br />
22.4 Get Ready<br />
1 a x(x 4) b y(2y 5) c (2x 1)(x 3)<br />
d (3y 4)(2y 5)<br />
2 a 8 b 1 c 149<br />
Exercise 22D<br />
1 a 0, 4 b 3, 5 c 0.5, 2.25<br />
d 0, 2 e 0, 1 f 0, 1.75<br />
2 a 2, 4 b 1, 6 c 3, 4<br />
d 3 e 9, 4 f 4, 4<br />
g 5<br />
h 10, 10<br />
3 a 5, 1_<br />
5<br />
b 3,<br />
2_<br />
3 c 1_<br />
2 , 4<br />
d 3, 1_<br />
5<br />
4 a 3, 2 b 5, 2 c 7, 3<br />
d 7, 5 e 3, 2.5 f 4 1_<br />
2 , 2_<br />
3<br />
g 8, 1 h 1, __ 9<br />
16<br />
686<br />
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<strong>Answers</strong><br />
22.5 Get Ready<br />
1 x 2 6x 9<br />
2 x 2 10x 25<br />
3 x 2 2ax a 2<br />
Exercise 22E<br />
1 a (x 2) 2 4 b (x 5) 2 25<br />
c (x 6) 2 36 d (x 1) 2 1<br />
e (x 7) 2 49 f (x 12) 2 144<br />
g (x 0.5) 2 0.25 h (x 1.5) 2 2.25<br />
i (x 2) 2 3 j (x 4) 2 1<br />
k (x 5) 2 45 l (x 3) 2 2<br />
m (x 10) 2 20 n (x 13) 2 170<br />
o (x 0.5) 2 0.75 p (x 2.5) 2 11.25<br />
2 a 2(x 3) 2 18 b 2(x 1) 2 3<br />
c 3(x 2) 2 2 d 5(x 5) 2 25<br />
3 a p 4, q 8 b 8<br />
4 a (0, 10) b (3, 1)<br />
5 a r 5, s 2 b 5 c x 2<br />
22.6 Get Ready<br />
1 x 2, x 2<br />
2 x 3, x 2<br />
3 x 7, x 4<br />
Exercise 22F<br />
1 a x 3 √ __<br />
11 b x 2 √ __<br />
3<br />
c x 5 √ __<br />
37 d x 1 2 √ __<br />
2<br />
e x 3 √ __<br />
_______ 15<br />
f x 6 √ __<br />
_________ 21<br />
2<br />
5<br />
2 a x 0.68, x 7.32 b x 8.27, x 0.73<br />
c x 2.37, x 3.37 d x 0.87, x 2.87<br />
e x 0.88, x 0.38 f x 0.93, x 0.43<br />
22.7 Get Ready<br />
1 x √ __<br />
14 2<br />
x 1.74, x 5.74<br />
2 x √ __<br />
14 3<br />
x 0.74, x 6.74<br />
3 x √ __<br />
8 1<br />
x 3.83, x 1.83<br />
Exercise 22G<br />
1 0.586, 3.41 2 0.807, 6.19<br />
3 0.606, 6.61 4 2.70, 3.70<br />
5 5.32, 1.32 6 4.30, 0.697<br />
7 0.293, 1.71 8 1.54, 0.260<br />
9 1.64, 0.811 10 0.322, 0.622<br />
11 1.39, 0.360 12 3.45, 1.45<br />
13 0.372, 5.37 14 5.11, 4.11<br />
15 1.72, 1.52<br />
22.8 Get Ready<br />
1 2x 2 9x 18<br />
2 6x 2 18x 12<br />
3 2x 12<br />
Exercise 22H<br />
1 x 0, x 5 2 x 2, x 1.8<br />
3 x 1.5, x 2 4 x 1, x _ 5<br />
9<br />
5 x 0.5, x 0.6 6 x 2, x 0.75<br />
7 x 2.30, x 1.30 8 x 4.48, x 3.73<br />
9 x 5.32, x 1.32 10 x 3.27, x 4.27<br />
11 x 0.576, x 10.4 12 x 3.41, x 0.586<br />
22.9 Get Ready<br />
1 4x 2x 2<br />
2 x 2 2x 1<br />
3 8 10x 3x 2<br />
Exercise 22I<br />
1 4, 6<br />
2 4<br />
3 12 and 48<br />
4 7.22 m<br />
5 a x 2 (x 1) 2 41<br />
2x 2 2x 40 0<br />
x 2 x 20 0<br />
b 4, 5 or 4, 5<br />
6 12.36 cm, 15.72 cm and 20 cm<br />
7 10 cm by 10 cm<br />
8 14 m or 16 m<br />
9 x 5<br />
10 54 km/h<br />
22.10 Get Ready<br />
1 a, d and e<br />
2, 3<br />
Exercise 22J<br />
5 cm<br />
1 y<br />
10<br />
b<br />
8<br />
6<br />
e<br />
d<br />
4 c<br />
2 b<br />
a<br />
10 8 6 4 2 O 2 4 6 8 10<br />
2<br />
4<br />
6<br />
8<br />
10<br />
a<br />
x<br />
687<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 687<br />
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<strong>Answers</strong><br />
2 y<br />
5<br />
4<br />
3<br />
2<br />
1<br />
5 4 3 2 1 O 1 2 3 4 5<br />
1<br />
2<br />
3<br />
4<br />
5<br />
(2.83, 2.83) and (2.83, 2.83)<br />
3 a y 1, y 11 b y 9, y 1<br />
c x 2, x 8 d x 10, x 0<br />
4 y x 12.49, y x 4.49<br />
22.11 Get Ready<br />
1<br />
2<br />
10 8<br />
x 3, y 7<br />
y<br />
10<br />
6 4 2<br />
O<br />
2<br />
y 3x 3<br />
10 8<br />
x 2, y 3<br />
8<br />
6<br />
4<br />
2<br />
4<br />
6<br />
8<br />
10<br />
y<br />
10<br />
8<br />
6<br />
4<br />
2<br />
6 4 2<br />
O<br />
2<br />
4<br />
6<br />
8<br />
10<br />
2<br />
2<br />
4 6 8 10<br />
y 2x 7<br />
y 2x 1<br />
x<br />
y x 10<br />
4 6 8 10<br />
x<br />
x<br />
Exercise 22K<br />
a graphs of the equations<br />
b :<br />
1 x 2, y 2; x 3, y 3<br />
2 x 4, y 7; x 2, y 1<br />
3 x 3, y 0.5; x 1, y 1.5<br />
4 x 1, y 1; x 1.67, y 6.33<br />
5 x 1, y 2; x 2, y 1<br />
6 x 3.5, y 21; x 0.5, y 3<br />
22.12 Get Ready<br />
1 y<br />
10<br />
8<br />
6<br />
4<br />
2<br />
10 8 6 4 2 O 2 4 6 8 10<br />
2<br />
4<br />
6<br />
8<br />
10<br />
2 y<br />
10<br />
8<br />
6<br />
4<br />
2<br />
10 8 6 4 2 O 2 4 6 8 10<br />
2<br />
4<br />
6<br />
8<br />
10<br />
3 y<br />
10<br />
8<br />
6<br />
4<br />
2<br />
10 8 6 4 2 O 2 4 6 8 10<br />
2<br />
4<br />
6<br />
8<br />
10<br />
x<br />
x<br />
x<br />
688<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 688<br />
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<strong>Answers</strong><br />
Exercise 22L<br />
1 x 2.7, y 5.4; x 2.7, y 5.4<br />
2 x 1.2, y 4.2; x 4.2, y 1.2<br />
3 x 6.8, y 1.8; x 1.8, y 6.8<br />
4 a x 2, y 3; x 3, y 2<br />
b x 4, y 2; x 2, y 4<br />
c x 2.2, y 5.4; x 3, y 5<br />
5 a x 0.449, y 4.45; x 4.45, y 0.449<br />
b x 1.49, y 5.46; x 2.09, y 5.26<br />
c x 5.63, y 8.26; x 3.23, y 9.46<br />
Review exercise<br />
1 a x 3 b x 6 c x 7.35<br />
2 a y 2 b t 2 c p 3<br />
3 3 cm<br />
4 a y 1 and y 6 b t 2 and t 2<br />
c p 1 and p 4<br />
5 a x 4_<br />
3 , y 25<br />
3 b x 1, y 1<br />
c x 2, y 5<br />
6 a x 2, y 2 b x 0.8, y 2.4<br />
7 29.12 m<br />
8 a h 0 when t 0 or 6, so the ball was in the air for 6<br />
seconds.<br />
b By symmetry of graph, maximum height is when t 3,<br />
giving height of 45 m<br />
c h 25 when t 1 or t 5, so the ball was 25 m above<br />
the ground after 1 second and 5 seconds.<br />
9 a k 0.5 and k 5 b m 0.5 and m 1.5<br />
c n __ 13 6<br />
10 a p 4, q 11 b x 4 √ __<br />
11<br />
11 x 6.27 and x 1.27<br />
12 a, b x 2.41 and x 0.414<br />
13 a (x 1) 2 2 b 2 c x 1<br />
d y<br />
3<br />
(1, 2)<br />
14 4(x 3) 2 36. a 4, p 3, q 36<br />
15 a x 2, y 2 b x 0, y 2<br />
c x 4, y 3<br />
16 F £12.50, g 5p<br />
17 y 2x 3 and 2y x 6<br />
18 x 5, y 8<br />
19 a p 4, q 7 b (4, 7)<br />
20 50p<br />
21 x 1, y 0 and x 1.33, y 9.33<br />
22 a 5(x 1) (4 3x)(x 2)<br />
5x 5 8 2x 3x 2<br />
3x 2 7x 13 0<br />
b x 1.22 and x 3.55<br />
23 a 5x x(2x 1) 95<br />
2x 2 6x 95 0<br />
b x 5.55 and x 8.55<br />
x<br />
24 a Time for first 10 km __ 10<br />
x<br />
Time for second 10 km _____ 10<br />
x 1<br />
Total time 4, so __ 10<br />
x _____ 10<br />
x 1 4<br />
b 10(x 1) 10x 4x(x 1)<br />
4x 2 24x 10 0<br />
c x 5.55 and x 0.450<br />
d 4.55 km/h<br />
25 a x 4.30, y 0.697 and x 0.697, y 4.30<br />
b x 0.350, y 6.70 and x 5.15, y 4.30<br />
26 x 3.41 and x 0.586<br />
27 x 2 y 2 16 is a circle with radius 4, centre the origin,<br />
so it intersects the x- and y-axes at 4. <strong>The</strong> point (1, 2)<br />
must lie inside this circle. <strong>The</strong>refore any straight line that<br />
passes through (1, 2) must intersect the circle twice.<br />
4<br />
y<br />
4<br />
4<br />
(1, 2)<br />
28 x 1.83, y 4.65 and x 2.63, y 4.25<br />
Chapter 23 <strong>Answers</strong><br />
23.1 Get Ready<br />
1 a 6 b<br />
4<br />
x<br />
1_<br />
6 c 1_<br />
9<br />
Exercise 23A<br />
1 a 1.75 cm b 17.6 cm c 64.9 m<br />
2 a 55.4 cm 2 b 9.25 cm 2 c 230 cm 2<br />
3 a 19.3 cm b 41.6 m<br />
4 70°<br />
5 5 cm<br />
6 a 1710 m 2 b 48.9 m<br />
7 a 57.9 cm b 235 cm 2<br />
23.2 Get Ready<br />
1 a 10a b 3b<br />
2 x 4.5<br />
Exercise 23B<br />
1 a 9 cm b m c 52 mm<br />
2 a 4 cm 2 b 100 m 2 c 400 m 2<br />
3 b 16 cm<br />
4 a 8 cm b 64 cm 2<br />
5 a 36 cm 2 b 4 cm c 36 4 cm<br />
6 Perimeter 1_ 1_ 1_<br />
Y X (X Y) (X Y)<br />
2 2 2<br />
689<br />
CS4-Z01_EMHA_SB_GCSE_0839_ANS.indd 689<br />
22/08/12 12:00 PM
<strong>Answers</strong><br />
23.3 Get Ready<br />
1 a 100 b 10 000 c 1000 000<br />
2 a 500 b 130 000 c 7 600 00<br />
3 a 70 b 0.35 c 0.049<br />
Exercise 23C<br />
1 a 45 239 cm 2 b 4.5239 m 2<br />
2 a 14 cm 2 b 1400 mm 2<br />
3 a 40 000 cm 2 b 69 000 cm 2 c 6 cm 2<br />
d 0.47 cm 2<br />
4 a 5 000 000 m 2 b 300 000 m 2 c 4 m 2<br />
d 0.056 m 2<br />
5 a 1000 b 1 000 000 c 8 300 000 mm 2<br />
6 a 44 800 cm 2 b 3.6 cm 2<br />
23.4 Get Ready<br />
1 a 2.211 cm 2 b 145.6 mm 2 c 65.0 mm 2 (to 3 s.f.)<br />
Exercise 23D<br />
1 a 60 m 3 b 480 cm 3 c 320 cm 3<br />
2 16 400 000 m 3<br />
3 a 100 cm 3 b 125 cm 3 c 0.0804 cm 3<br />
4 53 1_<br />
3 cm3<br />
5 1590 cm 3<br />
23.5 Get Ready<br />
1 a 10.24 b 32.2 cm 2 (to 3 s.f.)<br />
2 a 64 b 216 c 1331<br />
23.8 Get Ready<br />
1 15 cm 2 2 36.3 mm 2 (to 3 s.f.)<br />
Exercise 23H<br />
1 a 10 950 cm 2 b 11 700 cm 2 c 3524 cm 2<br />
d 3 m 2 e 684 cm 2 f 1392 cm 2<br />
2 £94<br />
23.9 Get Ready<br />
1 3.2 cm 2 7.2 cm 3 64.2 mm<br />
Exercise 23I<br />
1 a 240.3 cm 2 b 3.3 m 2<br />
2 a 503 cm 2 b 5890 mm 2 c 302 cm 2<br />
3 a 100 cm 2 b 80 cm 2 c 356 cm 2<br />
4 a 192 cm 2 b 924 cm 2<br />
23.10 Get Ready<br />
(1.5, 3)<br />
Exercise 23J<br />
1 O (0, 0, 0), A (4, 0, 0), B (4, 0, 3), C (0, 0, 3), D (0, 2, 3), E (0, 2, 0),<br />
F (4, 2, 0), G (4, 2, 3)<br />
2 y<br />
Exercise 23E<br />
1 268 cm 3 2 4090 m 3 3 8.31 cm<br />
4 17.9 cm 5 1940 cm 3 6 5.04 m<br />
C<br />
(1, 2, 3)<br />
A (1, 0, 0)<br />
x<br />
23.6 Get Ready<br />
1 a 6.28 cm 3 (to 3 s.f.) b 576 cm 3<br />
Exercise 23F<br />
1 a 223 cm 3 b 177 m 3 c 52.5 m 3 d 812 cm 3<br />
2 120 cm 3 3 54 000 cm 3 4 1610 cm 3<br />
5 731.25 cm 3 6 4_ 3 r3<br />
23.7 Get Ready<br />
1 a 1 000 000 000 b 4620 c 91.875 m 3<br />
Exercise 23G<br />
1 a 2 000 000 cm 3 b 6 750 000 cm 3 c 0.45 cm 3<br />
d 0.0068 cm 3<br />
2 a 7000 mm 3 b 3750 mm 3 c 25 mm 3<br />
3 a 0.075 m 3 b 0.0008 m 3 c 0.000 125 m 3<br />
4 a 0.83 l b 5.6 l c 1000 l d 0.003 54 l<br />
5 720 000 litres<br />
6 1277 cubes<br />
7 Volume A 12.5 m 3 and volume C 0.375 m 3 so shape A<br />
has the largest volume.<br />
z<br />
B (1, 0, 3)<br />
3 a O (0, 0, 0), A (4, 0, 0), B (4, 0, 3), C (0, 0, 3), D (0, 2, 0),<br />
E (4, 2, 0), F (4, 2, 3), G (0, 2, 3)<br />
b i (0, 2, 1.5) ii (4, 1, 1.5)<br />
4 (2, 3, 0), (2, 3, 1), (2, 0, 1)<br />
Review exercise<br />
1 96 cm 2<br />
2 110 cm 2<br />
3 8 000 000 cm 3<br />
4 a 4.5 cm 2 b 60 000 cm 2<br />
5 6.54 km 2<br />
6 a 905 m 3 b 4.92 m<br />
7 9.3 cm<br />
8 h __ 10<br />
9 x3 3x 2<br />
9 10.9 cm 2<br />
10 12 4<br />
11 a ___ 7<br />
b 4 ___ 7<br />
2<br />
2<br />
12 vol 2.7 litres<br />
13 a (5, 2, 0) b (2.5, 1, 3)<br />
690<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 690<br />
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<strong>Answers</strong><br />
14 h 9x<br />
15 1700 cm 3<br />
16 Yes. Volume of a pyramid 1_ base area height and<br />
3<br />
Volume of a cone 1_ base area height, so if the<br />
3<br />
base areas and volumes are the same, then the heights<br />
must also be equal.<br />
17 18.3 cm 2 (3 s.f.)<br />
Chapter 24 <strong>Answers</strong><br />
24.1 Get Ready<br />
a 0.05 b 0.4<br />
Exercise 24A<br />
1 a 700 m<br />
b <strong>The</strong>y stopped twice; once for 1 minute then again for<br />
2 minutes.<br />
c 9.5 minutes<br />
d 420 m<br />
2 a Month 1; 95 m b 80 m<br />
c Months 6 and 8. <strong>The</strong>se correspond to June and August<br />
when it doesn’t rain much.<br />
3 a 18:00 hours, because people are making their evening<br />
meals<br />
b 102 000 kilowatts c 12:00, 16:36, 20:00<br />
d 22:00<br />
24.2 Get Ready<br />
a A 63.5, B 64.25 b C 10.75 c D 54.9 d E 16.6<br />
Exercise 24B<br />
1 a<br />
14<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
0<br />
0 0.5 1 1.5 2 2.5 3 3.5<br />
Engine size (litres)<br />
b Negative correlation<br />
c <strong>The</strong> greater the engine size, the lower the petrol<br />
consumption.<br />
2 a<br />
900<br />
800<br />
700<br />
600<br />
500<br />
400<br />
300<br />
200<br />
100<br />
0<br />
8 9 10 11 12 13 14 15 16 17 18<br />
Screen size (inches)<br />
Petrol consumption (mpl)<br />
Selling price (£)<br />
b No correlation<br />
c Screen size and selling price are not related.<br />
3 a<br />
Number of fish<br />
190<br />
180<br />
170<br />
160<br />
150<br />
140<br />
130<br />
120<br />
0 2 4 6 8 10 12<br />
Year after restocking<br />
b Negative correlation<br />
c <strong>The</strong> more years have passed since restocking, the<br />
smaller the number of fish.<br />
4 a Related – the lighter the car, the faster it will go.<br />
b Related – the longer the motorway, the greater the<br />
number of petrol stations.<br />
c Unrelated<br />
d Related – the greater the number of bicycles sold, the<br />
greater the number of cycle helmets sold.<br />
Exercise 24C<br />
1 a, c<br />
800<br />
GNP (million £s)<br />
700<br />
600<br />
500<br />
400<br />
300<br />
200<br />
100<br />
0 5 10 15 20 25 30 35 40 45 50<br />
Energy consumption (kW/capital)<br />
b (20, 800)<br />
2 a, c<br />
Price (£1000)<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
0<br />
0 2 4 6 8 10 12 14<br />
Age (years)<br />
691<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 691<br />
05/09/12 5:21 PM
<strong>Answers</strong><br />
b Car prices cannot go negative, so the relationship only<br />
holds for cars up to 9 years old. Cars older than this will<br />
still be worth a small amount.<br />
3 a, b, d<br />
Mean low temperature (°F)<br />
80<br />
75<br />
70<br />
65<br />
60<br />
55<br />
50<br />
45<br />
40<br />
35<br />
30 40 50 60 70 80 90<br />
Mean high temperature (°F)<br />
c Ottawa. <strong>The</strong> high and low temperatures are the wrong<br />
way round.<br />
Exercise 24D<br />
1 a 44 b 65<br />
2 a i 65°F ii 78°F<br />
b i 45 degrees ii 17 degrees<br />
3 a<br />
Length (metres)<br />
2.464<br />
2.4635<br />
2.463<br />
2.4625<br />
2.462<br />
2.4615<br />
2.461<br />
20 25 30 35 40 45 50 55 60 65 70 75<br />
Temperature (°C)<br />
b i 41.5°C ii 63°C<br />
c 2.461 45 m<br />
Review exercise<br />
1<br />
No. of unemployed<br />
110<br />
100<br />
90<br />
80<br />
70<br />
60<br />
50<br />
40<br />
30<br />
20<br />
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec<br />
Month<br />
b 65<br />
c August, because more people go to the seaside in the<br />
summer holidays.<br />
2 a, b<br />
Art mark<br />
75<br />
70<br />
65<br />
60<br />
55<br />
50<br />
45<br />
40<br />
30 40 50 60 70 80 90 100<br />
Science mark<br />
c Negative correlation<br />
d <strong>The</strong> higher the science mark achieved by a student, the<br />
lower the art mark.<br />
3 a, d<br />
Temperature (°C)<br />
18<br />
16<br />
14<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
0<br />
0 2 4 6 8 10 12 14 16 18 20<br />
Height (100s metres)<br />
b Negative correlation<br />
c <strong>The</strong> greater the height above sea level, the lower the<br />
temperature.<br />
4 a, c<br />
Length (mm)<br />
94<br />
93.5<br />
93<br />
92.5<br />
92<br />
91.5<br />
91<br />
90.5<br />
90<br />
55 60 65 70 75 80 85<br />
Temperature (°C)<br />
b Positive. As temperature rises so does the length.<br />
d 0.14<br />
e For every rise of 10°C, the length increases by<br />
approximately 1.4 mm.<br />
5 a <strong>The</strong> higher the price, the fewer the number of cameras<br />
sold.<br />
692<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 692<br />
8/3/12 11:00:40 AM
<strong>Answers</strong><br />
b<br />
Number of cameras sold<br />
70<br />
60<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0<br />
60 65 70 75 80 85 90<br />
Price (£)<br />
6 a As a car gets older, its value decreases.<br />
b<br />
5000<br />
Value in pounds (£)<br />
4000<br />
3000<br />
2000<br />
1000<br />
c £2450<br />
d 1.9 years<br />
0<br />
0 1 2 3 4 5 6<br />
Age in years<br />
7 a <strong>The</strong> larger the weight of a child, the greater its height.<br />
b<br />
Height (cm)<br />
170<br />
165<br />
160<br />
155<br />
150<br />
145<br />
140<br />
35 40 45 50<br />
Weight (kg)<br />
c 155.5cm<br />
55<br />
8 a, c<br />
Weight (kg)<br />
90<br />
85<br />
80<br />
75<br />
70<br />
160 170 180 190<br />
Height (cm)<br />
200<br />
b Positive correlation<br />
c <strong>The</strong> taller the athlete, the greater his or her weight.<br />
Using the line of best fit above, 74.2 kg<br />
9 a, b, c<br />
Weight loss (lb)<br />
80<br />
70<br />
60<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0<br />
0 2 4 6 8 10 12 14 16 18 20 22 24<br />
Months taking drug<br />
c This is unlikely to be a genuine piece of data as the<br />
weight loss is so high in only 6 months.<br />
d Positive correlation<br />
e <strong>The</strong> drug is effective as the longer that the drug was<br />
taken, the greater the weight loss.<br />
10 a Positive correlation<br />
b <strong>The</strong> greater the amount of fertiliser used, the higher<br />
the crop yield.<br />
c 20 200 kg<br />
d 2.5 kg per 80 m 2<br />
e No, because there will be a limit on how high the crop<br />
yield can be, regardless of how much fertiliser is used.<br />
11 a, b<br />
3500<br />
Number of fleas<br />
c y k x<br />
3000<br />
2500<br />
2000<br />
1500<br />
1000<br />
500<br />
0<br />
0 2 4 6 8<br />
Day<br />
693<br />
CS4-Z01_EMHA_SB_GCSE_0839_ANS.indd 693<br />
22/08/12 12:00 PM
<strong>Answers</strong><br />
12 a For every 100 m rise in height above sea level there is<br />
1° drop in temperature.<br />
OR For every 1 m rise in height above sea level there is<br />
0.01° drop in temperature.<br />
b At sea level the air temperature is 19°.<br />
Chapter 25 <strong>Answers</strong><br />
25.1 Get Ready<br />
1<br />
__ 1<br />
16 2 __ 9<br />
25 3 8<br />
Exercise 25A<br />
1 a 1 b<br />
1_<br />
8 c 1_<br />
5 d 1<br />
e 1_<br />
8 f __ 1<br />
81 g ____ 1<br />
10 000 h 1<br />
i<br />
1_<br />
9 j 1 k 1 l ______ 1<br />
1 000 000<br />
2 a 3 b<br />
7_ c 49 d 64<br />
2<br />
e 16 f 15 5_<br />
8 g 1 h 5_<br />
9<br />
25<br />
i __<br />
49 j __ 27<br />
k 10 000 l 125<br />
64<br />
25.2 Get Ready<br />
1 a 1000 b<br />
2 10 4<br />
3 23 500<br />
Exercise 25B<br />
___ 1<br />
100<br />
1 a 7 10 5 b 6 10 2 c 2 10 3<br />
d 9 10 8 e 8 10 4<br />
2 a 600 000 b 10 000 c 800 000<br />
d 300 000 000 e 70<br />
3 a 4.3 10 4 b 5.61 10 5 c 5.6 10 1<br />
d 3.47 10 1 e 6 10 1<br />
4 a 39 600 b 68 000 000 c 8020<br />
d 57 e 9.23<br />
5 7 10 9<br />
6 4 10 4<br />
Exercise 25C<br />
1 a 5 10 3 b 4 10 2 c 7 10 6<br />
d 9 10 1 e 8 10 4<br />
2 a 0.000 06 b 0.08 c 0.000 000 5<br />
d 0.3 e 0.000 000 01<br />
3 a 4.7 10 3 b 9.87 10 1 c 8.034 10 4<br />
d 1.5 10 4 e 6.01 10 1<br />
4 a 0.000 084 3 b 0.0201 c 0.000 000 42<br />
d 0.7854 e 0.000 94<br />
5 a 4.57 10 5 b 2.3 10 3 c 3 10 4<br />
d 2.356 10 6 e 7.82 10 1 f 8.9 10 4<br />
g 2 10 2 h 5.26 10 3 i 6.034 10 3<br />
j 8.73 10 6<br />
6 a 0.000 412 b 3000 c 20 650 000<br />
d 0.000 004 e 327 000 000 f 0.75<br />
g 156.23 h 0.000 000 512 i 270 000<br />
j 0.612<br />
7 1 10 6 m<br />
8 6.25 10 2 mm<br />
Exercise 25D<br />
1 a 4.5 10 4 b 9.8 10 1<br />
c 3.4 10 1 d 1.86 10 12<br />
2 a 9 10 2 b 4.5 10 4<br />
c 3.708 10 13 d 6 10 10<br />
3 a In standard form<br />
b 8.9 10 8 c 1.32 10 4 d 5.6 10 8<br />
e 6 10 4 f In standard form<br />
g 4.005 10 12 h 9.08 10 18<br />
i In standard form j 4.6 10 5<br />
k 6.7 10 1 l 4 10 0<br />
4 6 290 000, 6.3 10 6 , 63.4 10 5 , 0.637 10 7<br />
5 0.000 033, 3.35 10 5 , 0.034 10 2 , 37 10 4<br />
Exercise 25E<br />
1 a 8 10 11 b 9 10 8 c 1.2 10 1<br />
d 4.3 10 5 e 2.5 10 8 f 1 10 4<br />
2 a 4 10 10 b 2.5 10 9 c 1.6 10 13<br />
d 4.9 10 15<br />
3 a 3.6 10 8 b 3.2 10 8 c 3.5 10 3<br />
d 1 10 14<br />
4 3.2 10 0 mm 2<br />
5 Time ________ Distance ________ 1.5 108<br />
Speed 3 10 5 5 102 seconds<br />
500 seconds 8 mins 20 secs<br />
6 160 m<br />
Exercise 25F<br />
1 a 2.1 10 8 b 2.4 10 5 c 5.2 10 0<br />
d 4.416 10 3 e 2.684 10 4 f 9.84 10 3<br />
g 9.6 10 13 h 9.84 10 17 i 9.6 10 15<br />
2 a 5.38 10 4 b 6.20 10 14 c 5.38 10 16<br />
d 6.20 10 6<br />
3 a 7.45 10 3 b 1.36 10 19 c 4.24 10 5<br />
d 3.28 10 12<br />
4 a 6 10 5 b 1.99 10 5 c 1.6 10 5<br />
5 1 : 30.1<br />
6 6.28 10 24<br />
25.3 Get Ready<br />
1 10 2 2 3 3<br />
Exercise 25G<br />
1 a 3 b 7 c 10<br />
d 2<br />
e<br />
1_<br />
2<br />
2 a 3 b 10 c 4<br />
d 5<br />
e<br />
1_<br />
2<br />
3 a<br />
1_<br />
2 b 1_<br />
2 c 1_<br />
5<br />
d 2<br />
e<br />
3_<br />
2<br />
4 a 9 b 100 c 16<br />
d 8 e 125<br />
1<br />
5 a __<br />
25 b ___ 1<br />
1000 c 1_<br />
3<br />
d<br />
1_<br />
4 e ___ 1<br />
512 f ___ 1<br />
625<br />
2<br />
g __<br />
25<br />
6 a n 1 b n 6 c n 1_<br />
2<br />
d n 5_<br />
2 e n __ 11<br />
3<br />
694<br />
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<strong>Answers</strong><br />
25.4 Get Ready<br />
1 1, 4, 9, 16, 25, 36, 49, 64, 81, 100<br />
2 a 6 b 10<br />
3 √ __<br />
9 , √ __<br />
64<br />
Exercise 25H<br />
1 a 2 b 3 c 5 d 4<br />
2 a 10 √ __<br />
2 b 4 √ __<br />
2 c 2 √ __<br />
5 d 2 √ __<br />
7<br />
3 x √ __<br />
30<br />
4 a 3 2 √ __<br />
3 b 5 3 √ __<br />
3 c 3 √ __<br />
5<br />
d 5 √ __<br />
7 e 7 4 √ __<br />
3 f 27 10 √ __<br />
2<br />
5 2 √ __<br />
10 cm<br />
6 a 12 cm b 4 cm 2<br />
7 3 2 √ __<br />
2 cm 2<br />
Exercise 25I<br />
√ __<br />
1 a ___ 2<br />
√ __<br />
b ___ 5<br />
√ __<br />
c ____ 10<br />
2<br />
5<br />
2<br />
d √ __<br />
2 √ __<br />
3<br />
2 e ____<br />
3<br />
2 a 1 √ __<br />
2 b 1 3 √ __<br />
2 c 1 2 √ __<br />
5<br />
d 1 4 √ __<br />
3 e 1 2 √ __<br />
7<br />
3 3 √ __<br />
____ 6<br />
2 c m 2<br />
4 a x 3 √ __<br />
7 b x 5 √ __<br />
11<br />
5 a 1.5 cm 2 b √ __<br />
22 cm<br />
Review exercise<br />
1 a 1 b<br />
1_<br />
4 c 1 d 1_<br />
8<br />
2 a 1 b 1 c<br />
1_<br />
3 d 1<br />
3 a 3 b 3 c<br />
1_<br />
2 d 8<br />
4 a 3 b 10 c 2 d 4<br />
5 a<br />
1_<br />
3 b 1_<br />
7 c 1_<br />
5 d 1_<br />
2<br />
6 a 2 b<br />
1_<br />
2<br />
7 a Mars b 1.4 10 9 km<br />
c Saturn d Neptune<br />
e Minimum distance from Earth to Mars <br />
2.3 10 8 1.5 10 8 8 10 7 km<br />
Speed ________ 8 107 9132 km/h<br />
365 24<br />
8 a i 7.9 10 3 ii 3.5 10 4<br />
b 5 10 7<br />
9 9.3 10 8<br />
10 n 5_<br />
2<br />
11 a k 3_<br />
2 b m 16 c √ __<br />
___ 2<br />
32<br />
12 9.43 10 12<br />
13 x 5.8 10 4<br />
14 a 1 10 9 b 2 10 8<br />
15 a x 2 b x 4 c x 3 d x 1_<br />
2<br />
16 Using a 2 b 2 (a b)(a b)<br />
______ 1<br />
√ __<br />
2 1 ________ 1<br />
√ __<br />
3 √ __<br />
2 ________ 1<br />
√ __<br />
4 √ __<br />
3 … ________ 1<br />
10 √ __<br />
99<br />
______ √__ 2 1<br />
2 1 √__ 3 √ __<br />
________ 2<br />
√__ 4 √ __<br />
________ 3<br />
… 10 √ __<br />
________ 99<br />
3 2 4 3 100 99<br />
1 10 9<br />
Chapter 26 <strong>Answers</strong><br />
26.1 Get Ready<br />
1 a 9 b 16 c 90<br />
2 a 196 b 625 c 384.16<br />
Exercise 26A<br />
1 720 cm 2 2 270 cm 2 3 12 cm 2<br />
4 1125 cm 2<br />
Exercise 26B<br />
1 a 18 b 15<br />
2 8 cm<br />
26.2 Get Ready<br />
1 a 7 b 10<br />
2 a 15.625 b 1331<br />
Exercise 26C<br />
1 270 cm 3 2 135 cm 3 3 1327 cm 3 4 2.25 cm 3<br />
Exercise 26D<br />
1 3 cm<br />
2 a 18 b 7<br />
3 a 28 b 1.2<br />
4 1.95 cm<br />
5 10 cm<br />
26.3 Get Ready<br />
1 2 : 9 2 4 : 5 3 1 : 6 4 1 : 1<br />
Exercise 26E<br />
1 1.6 cm 2 2 3.91 cm 3 3 2950 cm 2<br />
4 444 cm 2 5 a 292 cm 2 b 208 cm 2<br />
6 0.101 m 2<br />
Review exercise<br />
1 2.25 cm<br />
2 1.456 m<br />
3 12.96 cm 2<br />
4 a 20 cm b 6 cm<br />
5 a 320 cm 2 b 75 cm 3<br />
6 a 8 cm b 96 cm 3<br />
7 3800 cm 2<br />
8 a 1 : 4 b 1 : 8<br />
9 a All the edges of a cube are the same length, so the<br />
ratio between the edges of two cubes is a constant.<br />
b 1 : 6.25<br />
c <strong>The</strong> edges of a cuboid can be in any ratio, so two<br />
cuboids may not have the same ratio between every<br />
pair of edges.<br />
10 a 11.9 cm b 25.6 cm 2<br />
695<br />
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<strong>Answers</strong><br />
Chapter 27 <strong>Answers</strong><br />
27.1 Get Ready<br />
1 a 50p b 75p c £1 d £1.25<br />
2 a 20 seconds b 40 seconds<br />
c 80 seconds<br />
d 160 seconds<br />
Exercise 27A<br />
1 a<br />
Y<br />
16<br />
14<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
0<br />
0 2 4 6 8 10<br />
b Yes, the graph is a straight line through the origin<br />
2 k 0.4<br />
3 a<br />
9_<br />
4 ___ 22.5<br />
10 __ 36<br />
16 __ 45<br />
20 b k 2.25<br />
c 72<br />
4 a Y<br />
x<br />
b Y 1_<br />
2 t<br />
c Y 50<br />
5 a i £3.60 ii £5.40 iii £7.20<br />
b C 0.45v c 13 cm 3<br />
27.2 Get ready<br />
1 a x 18 b x 72 c x 75<br />
Exercise 27B<br />
1 k 1.5<br />
2 k 0.7<br />
3 a P h, so P kh<br />
When P 40.5, h 18, giving k 9_<br />
4<br />
So P 9_<br />
4 h<br />
b 72 c 12<br />
4 a V c, so V kc<br />
When V 10, c 0.04, giving k 250<br />
So V 250c<br />
b 0.036 amps<br />
5 a E ___ 7 m b 21 mm c 1125 g<br />
150<br />
6 66 2_<br />
3 cm3<br />
27.3 Get Ready<br />
1 a V kT b P kT<br />
x<br />
Exercise 27C<br />
1 a i M n ii M kn<br />
b i L h 2 ii L kh 2<br />
c i P t 3 ii P kt 3<br />
d i Q √ __<br />
y ii Q k √ __<br />
y<br />
e i W √ 3 __<br />
x ii W k √ 3 __<br />
x<br />
f i A __ 1 b<br />
g i H __ 1<br />
g 2<br />
h i U 1 __<br />
f 2<br />
i i E 1 ___<br />
w 3<br />
j i V 1 ___<br />
√ _ r<br />
ii A __ k b<br />
ii H __ k<br />
g 2<br />
ii U k __<br />
f 2<br />
ii E k ___<br />
w 3<br />
ii V k ___<br />
√ _ r<br />
2 a N d 2 b N kd 2<br />
3 H kc 2<br />
4 Q kt 3<br />
5 F is inversely proportional to the square of r<br />
6 T is proportional to the square root of l<br />
27.4 Get Ready<br />
1 a 225 b 512 c 1331 d 9 e 8 f 64<br />
Exercise 27D<br />
1 0.8<br />
2 16<br />
3 Z 1.28b 2<br />
4 L 1.875v 3<br />
5 4.5<br />
6 a 11.25 m b 14.1 m/s<br />
7 2.51 mm<br />
8<br />
Mass (grams) Length (cm)<br />
27.5 Get ready<br />
1 a P 1 __<br />
T<br />
Exercise 27E<br />
20 5<br />
34.56 6<br />
43.94 6.5<br />
50 6.79<br />
1 45<br />
2 a 2.5 b 6<br />
3 a 3.6 b 2.67<br />
4 2.67 m 3<br />
5 a 384 hertz b 0.96 m<br />
6 a 3.27 b 6.32<br />
7 a S ____ 8000<br />
f 2 b 500<br />
Review exercise<br />
1 0.75 0.5 2.25 1.5 5.25 3.5 6.75<br />
4.5 9.0 6.0 1.5<br />
2 a 960 b 560<br />
696<br />
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<strong>Answers</strong><br />
3 a T b b R is directly proportional to a<br />
c P m 2 d Z g 3<br />
e H is inversely proportional to y<br />
4 a S 1.5p<br />
b S<br />
12<br />
11<br />
10<br />
9<br />
8<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
O<br />
1 2 3 4 5 6 7 8 9 10<br />
5 £70 125<br />
6 Yes, the pressure will be 6 bars.<br />
7 10.2 units<br />
8 a<br />
D__<br />
t 2 __ 5 1 2 __ 20<br />
2 2 5<br />
9<br />
t 0 1 2 3 4 5<br />
D 0 5 20 45 80 125<br />
b 1.73 seconds<br />
Radius (r mm)<br />
p<br />
Resistance (R ohms)<br />
10 500<br />
15 222.22<br />
17.5 163.27<br />
14.14 250<br />
10 a X √ __<br />
h , so X k √ __<br />
h<br />
When X 3, h 16, giving k 0.75<br />
So X 0.75 √ __<br />
h<br />
b 3.75 c 64<br />
11 a T ____ 1<br />
√ m , so T ____ k<br />
√ m<br />
When T 20, m 50, giving k 100 √ __<br />
2<br />
__<br />
So T 100 √<br />
__ 2<br />
m<br />
b 88.9 g<br />
12 a A b C<br />
13 a 540 b 1.82<br />
14 a q ___ 136 b 5.44<br />
t 2<br />
15 51.6<br />
16 a y kz<br />
b u kv 2 v ___ l<br />
√ w<br />
v 2 __ l2<br />
w<br />
u k __ l2<br />
w<br />
uw kl 2<br />
kl 2 is a constant so uw is a constant.<br />
Chapter 28 <strong>Answers</strong><br />
28.1 Get Ready<br />
1<br />
0 1 1<br />
2<br />
Exercise 28A<br />
1 a<br />
2_<br />
2 a<br />
d<br />
3 a<br />
4 a<br />
d<br />
1<br />
5 ___<br />
500<br />
6 a<br />
7 a<br />
d<br />
8 a<br />
b i ___ 91<br />
181<br />
9 a<br />
1_<br />
10 0.3<br />
2<br />
0 1 1<br />
2<br />
7 b 4_<br />
7 c 1_<br />
7<br />
1_<br />
6 b 1_<br />
2 c __ 1<br />
13<br />
1_<br />
4 e __ 1<br />
26<br />
5_<br />
9 b 4_<br />
9 c 0<br />
1_<br />
2 b 1_<br />
2 c 1_<br />
4<br />
1_<br />
2 e 3_<br />
8<br />
3<br />
0 1 1<br />
2<br />
1_<br />
3 b 4_<br />
9 c 2_<br />
9 d 2_<br />
3<br />
__ 2<br />
11 b __ 1<br />
11 c __ 3<br />
11<br />
__ 4<br />
11 e 0<br />
Left-handed<br />
Righthanded<br />
Total<br />
Boys 47 135 182<br />
Girls 61 119 180<br />
Total 108 254 362<br />
54<br />
ii ___<br />
181<br />
__<br />
12<br />
6 b 7<br />
119<br />
iii ___<br />
362<br />
Exercise 28B<br />
1 a i 1<br />
36 ii 1_ 9 iii 1_ 6 b 1_<br />
6 c 1_<br />
9<br />
2 a<br />
H (1,H) (2,H) (3,H) (4,H) (5,H) (6,H)<br />
Coin<br />
T (1,T) (2,T) (3,T) (4,T) (5,T) (6,T)<br />
1 2 3 4 5 6<br />
Dice<br />
b i 1<br />
12 ii 1_ 2 iii 1_ 6<br />
3 a<br />
Spinner A<br />
b i 1_<br />
4<br />
Spinner B<br />
1 2 3 4<br />
1 0 1 2 3<br />
2 1 0 1 2<br />
3 2 1 0 1<br />
4 3 2 1 0<br />
ii<br />
1_<br />
8 iii 0<br />
697<br />
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<strong>Answers</strong><br />
4 a<br />
Spinner<br />
1 (1,1) (2,1) (3,1) (4,1) (5,1) (6,1)<br />
2 (1,2) (2,2) (3,2) (4,2) (5,2) (6,2)<br />
3 (1,3) (2,3) (3,3) (4,3) (5,3) (6,3)<br />
1 2 3 4 5 6<br />
Dice<br />
b i 1_ 6 ii 1_ 9 iii 1_ 3<br />
5 a R (R,R) (Bu,R) (Y,R) (Ba,R)<br />
Box B<br />
Y (R,Y) (Bu,Y) (Y,Y) (Ba,Y)<br />
6 3_ 5<br />
7 a<br />
Bu (R,Bu) (Bu,Bu) (Y,Bu) (Ba,Bu)<br />
R Bu Y Ba<br />
Box A<br />
b i __ 1<br />
12 ii 1_ 4 iii 3_ 4<br />
d<br />
1_<br />
6 b __ 1<br />
10 c __ 1<br />
60<br />
__ 1<br />
20 e __ 1<br />
12<br />
28.2 Get Ready<br />
1 a 0.4 b 0.65 c<br />
Exercise 28C<br />
3_<br />
5 d 1_<br />
6<br />
3<br />
1 a __<br />
10 b 2_<br />
5 c __ 7<br />
10<br />
2 0.9<br />
3 a 0.5 b 0.5 c 0.65 d 0.7<br />
3<br />
4 a __<br />
13 b __ 3<br />
13 c __ 1<br />
13<br />
6<br />
d __<br />
13 e __ 4<br />
13 f __ 4<br />
13<br />
5 a<br />
1_<br />
2 b __ 7<br />
18 c 2_<br />
9 d 2_<br />
3<br />
1<br />
6 a __<br />
26 b 1_<br />
2 c __ 5<br />
52<br />
7<br />
d __<br />
__<br />
26 e 7<br />
26<br />
7 0.35<br />
8 <strong>The</strong> events are not mutually exclusive. <strong>The</strong> probability is __ 1<br />
Exercise 28D<br />
1 11<br />
72<br />
2 4_ 5<br />
3 0.35<br />
4 0.25<br />
1<br />
5 a __<br />
13 b __ 12<br />
13<br />
6 a i 0.65 ii 0.85<br />
b 0.35 0.15 0.5 1<br />
7 a<br />
2_<br />
9 b 7_<br />
9 c 5_<br />
9<br />
8 0.6<br />
28.3 Get Ready<br />
1 a<br />
1_<br />
2 b 3_<br />
4 c 8_<br />
Exercise 28E<br />
9<br />
1 __<br />
20<br />
2 __ 13<br />
15<br />
9 d __ 3<br />
13<br />
36 .<br />
___ 77<br />
150<br />
3 a<br />
b No, red is almost three times as likely as orange.<br />
4 a Students’ own work<br />
b Drop the drawing pin more times, because the greater<br />
the number of trials, the more accurate the estimated<br />
probability.<br />
___ 33<br />
200<br />
5 , because the greater the number of trials, the more<br />
accurate the estimated probability.<br />
6 Students’ own work<br />
28.4 Get Ready<br />
1 a 50 b 18 c 30 d 40.5<br />
Exercise 28F<br />
1 50<br />
2 10<br />
3 30<br />
4<br />
Colour of peg Red White Yellow<br />
Expected number 25 125 100<br />
5 30<br />
6 No, the draw is random so he could be unlucky.<br />
7 a 20 b 65 c 80<br />
8 <strong>The</strong> doctor’s estimate is a bit high, as the results from the<br />
240 patients suggests a probability of 0.083.<br />
28.5 Get Ready<br />
1 a<br />
1_<br />
6 b 2_<br />
7 c 2_<br />
5 d __ 3<br />
16<br />
Exercise 28G<br />
1 0.32<br />
2 1_ 2<br />
3 0.6<br />
4 a 0.65 b 0.85 c 0.5525<br />
5 a<br />
1_<br />
4 b __ 1<br />
16 c ___ 3<br />
169<br />
1<br />
d ___<br />
676 e ___ 1<br />
2704<br />
6 a __ 3<br />
__<br />
__<br />
44 b 2<br />
11 c 15<br />
22<br />
28.6 Get Ready<br />
1 a<br />
3_<br />
4 b __ 8<br />
15 c __ 13<br />
20 d __ 55<br />
63<br />
Exercise 28H<br />
1 a Bag A Bag B Outcomes<br />
b i __ 12<br />
3<br />
5<br />
2<br />
5<br />
white<br />
blue<br />
35 ii __ 6<br />
35<br />
4<br />
7<br />
3<br />
7<br />
4<br />
7<br />
3<br />
7<br />
white<br />
blue<br />
white<br />
blue<br />
18<br />
iii __<br />
35<br />
ww<br />
wb<br />
bw<br />
bb<br />
12<br />
35<br />
9<br />
35<br />
8<br />
35<br />
6<br />
35<br />
698<br />
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<strong>Answers</strong><br />
2 a<br />
b<br />
3 a<br />
__ 21<br />
50<br />
First pencil Second pencil Outcomes<br />
3<br />
10<br />
7<br />
10<br />
HB<br />
not HB<br />
3<br />
10<br />
7<br />
10<br />
3<br />
10<br />
7<br />
10<br />
HB<br />
not HB<br />
HB<br />
not HB<br />
HB, HB<br />
HB, not HB<br />
not HB, HB<br />
not HB, not HB<br />
Ryan Ibrahim Outcomes<br />
3<br />
8<br />
5<br />
8<br />
orange<br />
red<br />
orange<br />
red<br />
orange<br />
red<br />
orange, orange<br />
orange, red<br />
red, orange<br />
red, red<br />
b i __ 3 ii __ 19<br />
20 40<br />
4 a i 0.6 ii 0.3<br />
b 1st lights 2nd lights Outcomes<br />
0.4<br />
0.6<br />
stopped<br />
not<br />
stopped<br />
0.7<br />
2<br />
5<br />
3<br />
5<br />
2<br />
5<br />
3<br />
5<br />
stopped<br />
stopped,<br />
stopped<br />
9<br />
100<br />
21<br />
100<br />
21<br />
100<br />
49<br />
100<br />
3<br />
20<br />
9<br />
40<br />
1<br />
4<br />
3<br />
8<br />
0.3 not stopped stopped, 0.12<br />
not stopped<br />
0.7<br />
0.3<br />
stopped<br />
not stopped<br />
not stopped,<br />
stopped<br />
not stopped,<br />
not stopped<br />
c i 0.28 ii 0.54 iii 0.82<br />
5 a Spinner A Spinner B Outcomes<br />
6<br />
12<br />
7 a<br />
0.3<br />
0.7<br />
6<br />
not 6<br />
0.45<br />
6 6, 6<br />
0.28<br />
0.42<br />
0.18<br />
0.55 not 6 6, not 6 0.165<br />
0.45<br />
0.55<br />
6<br />
not 6<br />
b i 0.385 ii 0.48 iii 0.315<br />
__ 5<br />
d<br />
___ 1<br />
169 b __ 9<br />
16 c 3_<br />
8<br />
___ 51<br />
1352 e __ 7<br />
16<br />
8 a HHH HTH HHT HTT<br />
THH TTH THT TTT<br />
b i 1_<br />
8<br />
9 0.243<br />
10 54<br />
28.7 Get Ready<br />
1 3_ 9 1_<br />
3<br />
ii<br />
3_<br />
8<br />
not 6, 6<br />
not 6, not 6<br />
0.135<br />
0.315<br />
0.385<br />
Exercise 28I<br />
1 b i __ 7<br />
15 ii __ 8<br />
15 iii __ 7<br />
15<br />
__<br />
33<br />
35<br />
ii 66<br />
15<br />
iii 22<br />
__ 3<br />
14<br />
___ 121<br />
b 4_<br />
7<br />
2 b i 5<br />
3 a<br />
4<br />
315<br />
5 0.74<br />
6 0.1325<br />
7 a<br />
2_<br />
7 b 2_<br />
7<br />
1<br />
8 a ___<br />
221 b __ 1<br />
17 c __ 13<br />
17<br />
37<br />
9 __<br />
49<br />
10 0.7816<br />
Review exercise<br />
4<br />
1 a __<br />
11 b __ 4<br />
11 c __ 7<br />
11<br />
7<br />
d __<br />
11 e __ 8<br />
11 f __ 3<br />
11<br />
23<br />
2 a __<br />
45 b __ 3<br />
10 c __ 8<br />
45<br />
37<br />
d __<br />
90 e __ 8<br />
45<br />
7<br />
3 __<br />
18<br />
4 a<br />
1_<br />
6 b 1_<br />
4 c __ 11<br />
24<br />
5 a 97 or 98 b 7 or 8 c 30<br />
6 Roll the dice 100 times, recording the results. If the dice<br />
is fair, each number should occur approximately 17 times.<br />
If Amy wanted to be more confident in her results, she<br />
could roll the dice more times.<br />
7 90<br />
8 a If Megan bought all the tickets, she is definitely right.<br />
Otherwise, she could be right, but there is no way of<br />
knowing because the winning tickets are drawn at<br />
random.<br />
b <strong>The</strong> winning tickets are chosen at random, so she may<br />
just have been lucky.<br />
__ _____<br />
9 a i b<br />
12<br />
10<br />
3_<br />
4<br />
ii<br />
(12 b)<br />
12<br />
b 3<br />
11 0.5525<br />
12 a 96<br />
b <strong>The</strong> original set of marked rabbits came from<br />
throughout the warren. <strong>The</strong> marked rabbits spread<br />
throughout the warren after being returned. <strong>The</strong> dye<br />
did not come off any rabbits.<br />
___ 5<br />
144<br />
13<br />
14 a<br />
b<br />
__ 2<br />
15<br />
Sarah<br />
4<br />
9<br />
5<br />
9<br />
Daffodil<br />
Hyacinth<br />
Jim<br />
3<br />
10<br />
7<br />
10<br />
3<br />
10<br />
7<br />
10<br />
Daffodil<br />
Hyacinth<br />
Daffodil<br />
Hyacinth<br />
15 a No. Horse C is more likely to win, because of the four<br />
possible outcomes, two are a head and tail, but two<br />
heads and two tails are each only one outcome.<br />
699<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 699<br />
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<strong>Answers</strong><br />
b No. Horse 7 is more likely to win, because of the 36<br />
possible outcomes from rolling two dice, a score of 7<br />
occurs more often than any other score.<br />
16 Number of possible selections of six numbers <br />
_________________<br />
40 39 38 37 36 35<br />
4 million<br />
6 5 4 3 2 1<br />
So P(choosing correct six numbers) 1 in 4 million<br />
17 ( 1_ ) 6 ____ 1<br />
2.1 105<br />
6 46 656<br />
18<br />
__<br />
4<br />
19<br />
1_<br />
5<br />
1<br />
20 a __<br />
12 b __ 5<br />
18 c __ 13<br />
18<br />
21 Students’ investigations<br />
Chapter 29 <strong>Answers</strong><br />
29.1 Get Ready<br />
1 ABF, ABE, AEF, BEF, BCF, BCG, BFG, CFG, CDG, CDH, CHG,<br />
DHG, ADE, ADH, AEH, DEH, ABC, ABD, ACD, BCD, EFG, EFH,<br />
EGH, FGH<br />
Exercise 29A<br />
1 a i 8.94 cm ii 13.6 cm iii 15.3 cm iv 15.8 cm<br />
b i 58.4° ii 72.9°<br />
2 AG 2 AC 2 CG 2 AB 2 BC 2 CG 2<br />
3 No. <strong>The</strong> longest needle that could fit in the box is 14 cm.<br />
4 5 cm<br />
5 a i 14.1 cm ii 7.07 cm<br />
b 13.2 cm c 61.9° d 56.2° e 14.1 cm<br />
f 70.5°<br />
29.2 Get Ready<br />
<strong>The</strong> diagrams could show the same pole viewed from different<br />
sides.<br />
Exercise 29B<br />
1 69.3°<br />
2 a i 51.3° ii 49.1° iii 38.7° b 90°<br />
3 a 470 m b 171 m c 985 m d 848 m<br />
4 a 15.6 m<br />
b i 26.6° ii 36.9° iii 22.6°<br />
5 a 86.5 cm b 63.9°<br />
6 a<br />
R<br />
P<br />
6 cm<br />
O<br />
6 cm<br />
b i 45° ii 45°<br />
c 1692 cm 3<br />
29.3 Get Ready<br />
6 cm<br />
1 a (u, v) b (u, v) c (u, v)<br />
2 a 0.5 and 0.5 b 0.64 and 0.64<br />
Q<br />
c sin 30° and sin 150° give the same answer.<br />
cos 50° and cos 130° give the same value, but opposite<br />
signs.<br />
Exercise 29C<br />
1 a<br />
b<br />
y<br />
1<br />
0.5<br />
360 180 O 180 360<br />
0.5<br />
1<br />
y<br />
1<br />
0.5<br />
360 180 O 180 360<br />
0.5<br />
1<br />
2 a 30, 150 b 84.3, 275.7<br />
3 a sin ° 1_ so 19.5<br />
3<br />
b 19.5, 160.5, 379.5, 520.5<br />
4 a cos ° 0.3 so 107.5<br />
b 252.5, 107.5, 107.5, 252.5<br />
29.4 Get Ready<br />
1 a 30 cm 2 b 54 cm 2 c 18.4 cm 2<br />
Exercise 29D<br />
1 a 21.9 cm 2 b 29.2 cm 2 c 15.4 cm 2<br />
d 30.0 m 2<br />
2 16.8 m<br />
3 33.3°<br />
4 a 11.4 cm 2 b 11.4 cm 2<br />
c <strong>The</strong> answers are the same because sin 25° sin 155°.<br />
5 a 45° b 12.7 cm 2 c 102 cm 2<br />
6 3.41 cm 2<br />
29.5 Get Ready<br />
1 a 0.866 b 13.6<br />
Exercise 29E<br />
1 a 8.06 cm b 7.19 cm c 6.35 cm<br />
d 9.01 cm e 15.0 cm<br />
f f 6.06 cm, g 11.4 cm<br />
29.6 Get Ready<br />
1 35.2°<br />
Exercise 29F<br />
1 a 45.0° b 63.6° c 23.6°<br />
d d 43.3°, e 63.7°<br />
2 a 13.3 cm b 39.3° c 154.7°<br />
θ<br />
θ<br />
700<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 700<br />
8/3/12 11:00:46 AM
<strong>Answers</strong><br />
3 a 9.72 cm b 9.89 cm c 37.9 cm 2<br />
4 a 66.0° b 7.63 cm<br />
5 a i 42° ii 55°<br />
b 9.79 km c 11.9 km d 6.55 km<br />
29.7 Get Ready<br />
1 a 11 b 3 c 22.4<br />
2 3.82<br />
Exercise 29G<br />
1 a 8.80 cm b 12.6 cm c 5.01 cm<br />
d 8.42 cm e 15.3 cm f 16.1 cm<br />
2 12.6 cm<br />
29.8 Get Ready<br />
1 a 50.8° b 72.3° c 54.8°<br />
Exercise 29H<br />
1 a 54.7° b 81.2° c 46.0° d 131.2°<br />
2 103.6°<br />
3 a 68° b 91.0 m<br />
4 a 22.4 cm b 127.7° c 161 cm 2<br />
5 16.7 km<br />
6 7.71 cm, 11.9 cm<br />
29.9 Get Ready<br />
1 a cosine rule b sine rule<br />
c sine rule or cosine rule<br />
Exercise 29I<br />
1 a 70.5°, 59.0°, 50.5° b 42.4 cm 2<br />
2 a 9.68 cm b 42.9° c 17.7 cm<br />
3 a 7.32 cm b 6.65 cm c 78.7°<br />
4 a 6.76 cm b 75° c 13.1 cm d 19.9 cm<br />
5 a 039° (or 321°) b 148° (or 212°)<br />
6 50°<br />
7 a 70° b 4.43 m<br />
8 a 73.2° b 26.2 m c 67.3° d 22.6°<br />
9 20.5 km<br />
Review exercise<br />
1 13 cm<br />
2 85.5°<br />
3 5.89 cm<br />
4 a 9.11 cm b 19.2°<br />
5 18.3 cm<br />
6 76.3°<br />
√ __<br />
3<br />
7 a ___ b ___ √__ 3<br />
2<br />
2<br />
8 42° and 318°<br />
9 10.9 cm 2<br />
10 a 105.7° b 10.7 cm 2<br />
11 22.2°<br />
12 a 21.8 cm b 66.4 cm 2<br />
13 11.1 cm<br />
14 a 41.4° b 17.8 cm<br />
15 a 4.51 cm b 37°<br />
Chapter 30 <strong>Answers</strong><br />
30.1 Get Ready<br />
1 18 2 x __ 11<br />
4<br />
Exercise 30A<br />
3 y (t 1)2<br />
1 a 12 b 0 c 48<br />
d 1 e 4 f 8<br />
2 a 4 b 28 c 96<br />
d 6.4<br />
3 a 8 b 2<br />
4 a i 4 ii 3 iii 0 b 4, 4<br />
5 a i 18 ii 12 iii 30 b 3, 4<br />
6 a i 3 ii 4 iii 10 b 0, 4 c 1, 5<br />
7 a 16 b x 2 4 c (x 4) 2<br />
8 a 8 b 4(2x 1) c 12(x 1)<br />
30.2 Get Ready<br />
1 (2, 5) 2 (4, 3) 3 (1, 3)<br />
Exercise 30B<br />
1 a<br />
b<br />
c<br />
y<br />
12<br />
10<br />
8<br />
6<br />
4<br />
O<br />
6 4 2<br />
2<br />
2<br />
y<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
6 4 2<br />
O<br />
2<br />
4<br />
y<br />
10<br />
8<br />
6<br />
4<br />
2<br />
6 4 2<br />
O<br />
2<br />
4<br />
2<br />
2<br />
2<br />
4 6<br />
4 6<br />
4 6<br />
x<br />
x<br />
x<br />
701<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 701<br />
7/30/12 5:24:07 PM
<strong>Answers</strong><br />
d<br />
2 a i<br />
ii<br />
y<br />
10<br />
8<br />
6<br />
4<br />
2<br />
6 4 2<br />
O<br />
2<br />
4<br />
y<br />
4<br />
y f(x) 3<br />
2<br />
2<br />
2<br />
O<br />
2<br />
4<br />
y<br />
O<br />
2<br />
4<br />
b i (0, 3) ii (1, 0)<br />
3 a<br />
y<br />
y f(x) 2<br />
4<br />
2<br />
2<br />
b (2, 2.5)<br />
c i y f(x) 2<br />
d<br />
y<br />
y f(x 2)<br />
20<br />
15<br />
10<br />
5<br />
4 2<br />
O<br />
5<br />
10<br />
15<br />
20<br />
2<br />
4 6<br />
y f(x)<br />
2<br />
x<br />
x<br />
y f(x)<br />
y f(x 1)<br />
4<br />
2<br />
O<br />
2<br />
4<br />
2<br />
x<br />
y f(x) 2<br />
2<br />
x<br />
ii y 1 __<br />
x 2<br />
y f(x)<br />
2<br />
4<br />
x<br />
7 a a 2, b 5 b Translation of ( 2 5)<br />
c, d<br />
y x 2 4x 9<br />
8 Translation by (<br />
0<br />
6)<br />
30.3 Get Ready<br />
1<br />
2<br />
y<br />
10<br />
9<br />
8<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
(2, 5)<br />
0<br />
0 1 2 3 4 5 6 7 8 9 10<br />
y<br />
O<br />
y x 2<br />
<strong>The</strong> first triangle has been stretched by a factor of 2 parallel<br />
to the x-axis.<br />
y<br />
10<br />
9<br />
8<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
0<br />
0 1 2 3 4 5 6 7 8 9 10<br />
<strong>The</strong> first triangle has been stretched by a factor of 3 parallel<br />
to the y-axis.<br />
x<br />
x<br />
x<br />
1<br />
e p 1, q 4 f i y f(x 2) ii y ____<br />
4 a (3, 2) b (1, 5)<br />
5 a Translation by 3 units parallel to the y-axis.<br />
b y f(x) 3 c y 4x x 2 3<br />
6 a Translation by 2 units parallel to the x-axis.<br />
b y f(x 2)<br />
c y (x 2) 2<br />
x 2<br />
702<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 702<br />
7/30/12 5:24:20 PM
<strong>Answers</strong><br />
Exercise 30C<br />
1 y f(2x)<br />
10<br />
b<br />
y<br />
4<br />
8<br />
2<br />
6<br />
y f(x)<br />
4<br />
2<br />
O<br />
2 4<br />
x<br />
2<br />
(2, 2) is mapped to the point (1, 2)<br />
2 a<br />
y y 4f(x)<br />
c<br />
O<br />
2<br />
y<br />
4<br />
90<br />
180 270 360 450 540<br />
x<br />
2<br />
y f(x)<br />
O<br />
x<br />
b y 4x 2<br />
c Stretch of magnitude 4 parallel to the y-axis<br />
Stretch of magnitude 1_ parallel to the x-axis<br />
2<br />
3 a<br />
2<br />
1<br />
b<br />
4 a<br />
O<br />
1<br />
2<br />
y 2 cos x °<br />
2<br />
1<br />
O<br />
1<br />
2<br />
90 180 270 360 450 540 630 720<br />
90 180 270 360 450 540 630 720<br />
y cos(2x°)<br />
y<br />
20<br />
10<br />
2 1<br />
O<br />
10<br />
20<br />
b (0, 4) is mapped to (0, 12). ( 2_<br />
3<br />
5 a y<br />
4<br />
2<br />
1<br />
2<br />
x<br />
x<br />
x<br />
, 0 ) is mapped to (<br />
2_<br />
3 , 0 )<br />
6 a<br />
O<br />
2<br />
2<br />
1<br />
O<br />
1<br />
2<br />
90 180 270 360 450 540<br />
x<br />
90 180 270 360 450 540 630 720 810 900 990 1080<br />
b 1 solution<br />
7 a Stretch of magnitude 2 parallel to the x-axis.<br />
b y<br />
4<br />
O<br />
4<br />
2 4 6 8<br />
c i y f (<br />
__ x 2 ) ii y __ x __<br />
2 ( x 2 4 )<br />
8 a p 4, q 11<br />
b (0, 5)<br />
c Stretch parallel to the y-axis of magnitude 0.6.<br />
0.6 (x 2 8x 5)<br />
Exercise 30D<br />
1 a y<br />
2<br />
1<br />
O<br />
1<br />
2<br />
90 180 270 360 x<br />
x<br />
x<br />
O<br />
2<br />
90<br />
180 270 360 450 540<br />
x<br />
b y 2 sin ( x __<br />
2 )<br />
703<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 703<br />
05/09/12 5:22 PM
<strong>Answers</strong><br />
2 a y<br />
14<br />
8 7 6 5 4 3 2 1 O 1 2 3 4 5<br />
2<br />
b y 2f ( x __<br />
2 )<br />
c<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
4<br />
y<br />
14<br />
12<br />
x<br />
30.4 Get Ready<br />
1<br />
y<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
6 5 4 3 2 1<br />
O<br />
1<br />
2<br />
3<br />
4<br />
5<br />
5<br />
1<br />
2 3 4 5 6<br />
x<br />
10<br />
8 7 6 5 4 3 2 1 O 1 2 3 4 5<br />
2<br />
8<br />
6<br />
4<br />
2<br />
4<br />
x<br />
2<br />
y<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
3 a, b<br />
y<br />
3<br />
2<br />
1<br />
O<br />
1<br />
90 180 270 360 450 540 630 720 810 900 990 1080 x<br />
6 5 4 3 2 1<br />
O<br />
1<br />
2<br />
3<br />
4<br />
5<br />
5<br />
1<br />
2 3 4 5 6<br />
x<br />
2<br />
3<br />
3<br />
y<br />
6<br />
4 a 4 __<br />
( x2<br />
16 3 ) b 4 __<br />
( 4 x 1 )<br />
c 4 2 x_<br />
4<br />
2 x_<br />
4 2 d 8 sin ( x __<br />
2 )<br />
5<br />
4<br />
3<br />
2<br />
1<br />
6 5 4 3 2 1<br />
O<br />
1<br />
1<br />
2 3 4 5 6<br />
x<br />
2<br />
3<br />
4<br />
5<br />
5<br />
704<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 704<br />
05/09/12 5:22 PM
<strong>Answers</strong><br />
Exercise 30E<br />
1 a<br />
y<br />
4 a<br />
y<br />
6<br />
5<br />
y f(x) 2<br />
4<br />
O<br />
x<br />
3<br />
2<br />
1<br />
b y (x 2 3)<br />
2 a<br />
y<br />
y f(x)<br />
y f(x)<br />
5 4 3 2 1 O<br />
1<br />
2<br />
3<br />
4<br />
1 2 3 4 5 6 7 8<br />
x<br />
3 a<br />
O<br />
b p 2, q 8 c y x 3<br />
4<br />
y f(x)<br />
2<br />
b (r 1, t 2)<br />
Review exercise<br />
y<br />
10<br />
5<br />
O<br />
5<br />
10<br />
x<br />
2 4<br />
c y 2 x<br />
y f(x)<br />
1 a 6 b 11 c a = 0<br />
2 f(x 1) (x 1) 2 3(x 1) x 2 x 2<br />
(x 2)(x 1)<br />
3<br />
y<br />
y x 2<br />
x<br />
b<br />
y<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
5 4 3 2 1 O<br />
1<br />
1 2 3 4 5 6 7 8<br />
2<br />
y f(x)<br />
3<br />
4<br />
5 f(x 4)<br />
6 a, b y<br />
5<br />
b<br />
4<br />
3<br />
a<br />
2<br />
1<br />
x<br />
y x 2<br />
x<br />
2 1 O 1 2 3<br />
1<br />
c x 1 and x 2<br />
7 a (180, 0)<br />
b y<br />
x<br />
O<br />
A<br />
x<br />
705<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 705<br />
7/30/12 5:24:33 PM
<strong>Answers</strong><br />
8 y<br />
4<br />
3<br />
2<br />
1<br />
O<br />
1<br />
2<br />
3<br />
4<br />
90 180 270 360 x<br />
9 Translation by (<br />
4<br />
5)<br />
10 a, b Stretch parallel to the y-axis of magnitude 4<br />
Stretch parallel to the x-axis of magnitude 0.5<br />
11 a p 2, q 12<br />
b (2, 12)<br />
c Stretch parallel to the y-axis of magnitude 2<br />
d y 2f(x)<br />
Chapter 31 <strong>Answers</strong><br />
31.1 Get Ready<br />
a 20° b 65° c 40°<br />
Exercise 31A<br />
1 a 25°<br />
2 b 33°<br />
3 c 40°<br />
4 d 19° (angles on a line, isosceles triangle in a circle)<br />
5 e 60°, f 40°, g 100° (equilateral triangle, isosceles<br />
triangle in a circle)<br />
6 h 54°, i 126°, j 27° (right-angled triangle, angles on a<br />
line, isosceles triangle in a circle)<br />
31.2 Get Ready<br />
1 a 33°, b 57°, c 90°<br />
Exercise 31B<br />
1 a 50° 2 b 59°<br />
3 c 136° 4 d 66°, e 24°<br />
5 f 60° 6 g 107°<br />
31.3 Get Ready<br />
1 a 28° b 49° c 57°<br />
Exercise 31C<br />
1 a 83°<br />
2 b 90°, c 52°<br />
3 d 64°, e 38°<br />
4 f 110°, g 55°<br />
5 h 30°<br />
6 i 72°<br />
7 j 49°<br />
<strong>The</strong> line drawn from the centre of a circle to the midpoint<br />
of a chord is perpendicular to that chord.<br />
8 k 68°<br />
<strong>The</strong> angle at the centre of a circle is twice the angle at the<br />
circumference, both subtended by the same arc.<br />
9 l 90°<br />
<strong>The</strong> angle in a semicircle is a right angle.<br />
10 a angle DAB 65°<br />
<strong>The</strong> angle at the centre of a circle is twice the angle at the<br />
circumference, both subtended by the same arc.<br />
b reflex angle DOB 230°<br />
Angles about a point add up to 360°<br />
c angle BCD 115°<br />
<strong>The</strong> angle at the centre of a circle is twice the angle at the<br />
circumference, both subtended by the same arc so reflex<br />
angle BOD is twice angle BCD.<br />
31.4 Get Ready<br />
1 a 93° b 94° c 46°<br />
Exercise 31D<br />
1 a 40°<br />
2 b 82°<br />
3 c 38°<br />
4 d 50°, e 100°, f 40°<br />
5 g 58°<br />
6 h 74°<br />
7 i 71°<br />
Angles in the same segment are equal so angle SQR 31°,<br />
and angles in a triangle add up to 180°.<br />
8 j 35°<br />
Opposite angles of a cyclic quadrilateral add up to 180° and<br />
the base angles of an isosceles triangle are equal.<br />
9 k 57°<br />
<strong>The</strong> angle between a tangent and a chord is equal to the<br />
angle in the alternate segment and the angles on a straight<br />
line (or in a triangle) add up to 180°.<br />
Review exercise<br />
1 angle OAD 90° (angle between tangent and radius)<br />
angle AOD 180 90 36 54° (angle sum in a<br />
triangle)<br />
angle ABC 1_ 54 27° (angle at centre is twice angle<br />
2<br />
at circumference)<br />
2 a i 140°<br />
ii <strong>The</strong> angle at the centre of a circle is twice the angle<br />
at the circumference, both subtended by the same<br />
arc.<br />
b i 110°<br />
ii <strong>The</strong> opposite angles of a cyclic quadrilateral add up<br />
to 180°.<br />
3 a 134°, b 42°<br />
4 d 90°, e 67°, f 67°<br />
5 g 33°, h 33°<br />
6 o 51° (angles in the same segment are equal)<br />
p 26° (angles in an isosceles triangle add up to 180°;<br />
angle between a tangent and a chord is equal to the angle<br />
in the alternate segment).<br />
7 s 94° (angles on a straight line add up to 180°; opposite<br />
angles of a cyclic quadrilateral add up to 180°)<br />
706<br />
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<strong>Answers</strong><br />
8 t 52° (angle between a tangent and a radius is a right<br />
angle; angles in a triangle add up to 180°)<br />
u 26° (angle at the centre of a circle is twice the angle<br />
at the circumference, both subtended by the same arc)<br />
9 angle CBT angle CBA (BC bisects angle ABT)<br />
angle CBT angle CAB (angle between tangent and<br />
chord is equal to angle in alternate segment)<br />
angle CBA CAB<br />
So triangle CAB is isosceles and CA CB<br />
10 angle PMA 1_ 132 66° (angle at the centre is twice<br />
2<br />
angle at circumference)<br />
angle MAT 66° (alternate angles, PM parallel to AT)<br />
angle OAT 90° (angle between tangent and radius)<br />
angle OAM 90 66 24°<br />
OA OM (radii), so triangle AOM is isosceles<br />
angle OMA 24° (base angles of isosceles triangle)<br />
11 OR OP (radii), so triangle ORP is isosceles<br />
angle OPR ________ 180 20<br />
80° (angle sum of isosceles<br />
2<br />
triangle)<br />
OQ OP (radii), so triangle OQP is isosceles<br />
angle OPQ _________ 180 100<br />
40° (angle sum of isosceles<br />
2<br />
triangle)<br />
So angle OPQ 1_ angle OPR and QP bisects angle OPR<br />
2<br />
Chapter 32 <strong>Answers</strong><br />
32.1 Get Ready<br />
1 a (x 4)(x 1)<br />
b (x 3)(x 2)<br />
c (2x 1)(x 3)<br />
Exercise 32A<br />
1 a 2x 3 b<br />
e 2x<br />
2 a _____ x 1<br />
x 2<br />
b<br />
3 a _____ x 1<br />
x<br />
b<br />
4 a ______ 2x 3<br />
3x 2<br />
b<br />
5 a _____ x 5<br />
x 5<br />
b<br />
d _____ 3 x<br />
x 3<br />
e<br />
32.2 Get Ready<br />
___ x<br />
3y<br />
_____ x 1<br />
x<br />
_____ 4x<br />
x 6<br />
______ 5x 3<br />
3x 2<br />
_______ x 5<br />
2(x 5)<br />
2 x _____<br />
x 2<br />
c _____ x 5<br />
2<br />
c _____ x 2<br />
x 4<br />
2(x 2)<br />
c _______<br />
x 2<br />
c ______ 3x 1<br />
3x 1<br />
c ______ 2x 1<br />
2x<br />
f (x 4)<br />
d x<br />
1 a 30 b 12x c x(x 1)<br />
Exercise 32B<br />
1 a x b 2x c<br />
e<br />
x__ f ___ 5<br />
5<br />
3x<br />
2 a ___ 7x<br />
b<br />
x__<br />
12<br />
3<br />
c<br />
e ___ 5<br />
f ___ 1<br />
6x<br />
4x<br />
3 a ______ 5x 2<br />
b ______ 9x 7<br />
6<br />
20<br />
c<br />
7 ___<br />
10x<br />
3x ___<br />
8<br />
x__<br />
9<br />
d<br />
d<br />
d<br />
d<br />
d<br />
_____ x 4<br />
x 3<br />
_____ x 3<br />
x<br />
______ x 1<br />
2x 3<br />
4x ___<br />
9<br />
5x ___<br />
6<br />
d<br />
f<br />
____________ 2x 5<br />
(x 2)(x 3)<br />
______________ 4<br />
(2x 1)(2x 3)<br />
Exercise 32C<br />
e<br />
x 2 ____________<br />
(x 2)(x 1)<br />
1 a i 2(x 1) ii 6(x 1)<br />
b 6(x 1)<br />
c _______ 2<br />
3(x 1)<br />
2 a 15x b (x 2)(x 3)<br />
c x(x 1) d (x 1)(x 2)<br />
e 2(x 3) f x(x 1)<br />
3 a (x 1)(x 2) b ____________ x<br />
(x 1)(x 2)<br />
4 a (x 2)(x 2) b ____________ 3x 4<br />
(x 2)(x 2)<br />
5 a (2x 1)(x 1) b ______ 1<br />
(x 1)<br />
6 _____________ x 1<br />
2(x 1)(x 3)<br />
7 ___________<br />
2x 2 7x 4<br />
8x(x 1)<br />
8 ____________ 3x<br />
(3 x)(3 x)<br />
9 a i (x 4)(x 5) ii (x 5)(x 6)<br />
b _________________<br />
3x 20<br />
(x 4)(x 5)(x 6)<br />
10 ____________________<br />
4<br />
(2x 1)(2x 1)(2x 3)<br />
32.3 Get Ready<br />
1 a a b<br />
Exercise 32D<br />
1 a __ x 2<br />
15<br />
xy<br />
2 a ___<br />
2<br />
3 a<br />
5__<br />
9<br />
4 a __ 27<br />
4<br />
(x 1)<br />
5 a _______<br />
2<br />
2<br />
d<br />
1__<br />
6<br />
b<br />
b<br />
b<br />
b<br />
__ 12<br />
y 2<br />
___ 2x<br />
9<br />
____ 5xy<br />
18<br />
___ 5x<br />
8<br />
1_<br />
2 c _____ x 3<br />
x 1<br />
c ____ 15xy<br />
8<br />
c<br />
6__<br />
y<br />
c x²y²<br />
c<br />
b (x 2)(x 1)<br />
e 3(3x 1)<br />
6 a (x 2)(x 2) b<br />
d<br />
d<br />
d<br />
_______ x(x 3)<br />
12<br />
_______ 2(x 1)<br />
x 1<br />
________ 2x(x 2)<br />
(x 1) 2<br />
___ 7x<br />
2y 2 d _____ 2x<br />
x 5<br />
c _____ x<br />
______ x 2<br />
x 2 4<br />
7 a i (x 1)(x 4) ii (x 2)(x 4)<br />
(x 2)(x 3)<br />
b ____________<br />
(x 1) 2<br />
8 x 1<br />
32.4 Get Ready<br />
f<br />
x 2<br />
_______ 3(x 4)<br />
4<br />
1 a even b either c odd d either<br />
e either<br />
Exercise 32E<br />
1 (2n 1) 2m 2(m n) 1<br />
707<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 707<br />
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<strong>Answers</strong><br />
2 1_ 1_<br />
[n (n 1) (n 2) (n 3)] [4n 6] 2n 3<br />
2 2<br />
3 n (n 1) (n 2) 3n 3 3(n 1)<br />
4 a (2n 1)2m 2[m(2n 1)]<br />
b (2n 1)(2m 1) 4mn 2m 2n 1<br />
2(2mn m n) 1<br />
c (2n)(2m) 4mn 2(2mn)<br />
5 (m n)(m n) m² nm mn n² m² n²<br />
6 (n 4)² n² n² 8n 16 n² 8n 16 8(n 2)<br />
Review exercise<br />
1 n (n 1) (n 2) (n 3) 4n 6<br />
(n 3)(n 2) n(n 1) (n 2 5n 6) (n 2 n)<br />
4n 6<br />
2 a<br />
e<br />
3 a<br />
d<br />
f<br />
__ x 2<br />
2<br />
_____ x<br />
x 3<br />
x__<br />
2<br />
b<br />
f<br />
b<br />
_______ (x 1) 2<br />
3<br />
_____ x 5<br />
x 5<br />
13 ___<br />
6x<br />
____________ 2x 7<br />
(x 1)(x 2)<br />
____________ 2<br />
(x 1)(x 5)<br />
4 a 2 b x c<br />
e<br />
____________ x 1<br />
(x 1)(x 3)<br />
c x<br />
g<br />
c<br />
e<br />
_______ x 1<br />
x(x 1)<br />
d<br />
h<br />
______________ 10x<br />
(5x 3)(5x 3)<br />
_______ x 2<br />
(x 1) 2<br />
2__<br />
5<br />
f 1 g<br />
_____ x 1<br />
x 2<br />
x 4 ______<br />
3x 2<br />
d ___ 2s 2<br />
3<br />
2_<br />
3 h ______ 2x 1<br />
x<br />
5 a (n 1)(n 2) n(n 1) n² 3n 2 n² n<br />
2n² 4n 2<br />
2(n² 2n 1)<br />
2(n 1)²<br />
b 2(n 1)² is always even.<br />
6 (2n 1)² (2n 1)² (4n² 4n 1) (4n² 4n 1)<br />
8n<br />
100 (x<br />
7 __________________<br />
2 16x 64)<br />
____________<br />
36 16x x2<br />
_____________<br />
(2 x)(18 x)<br />
4<br />
4<br />
4<br />
8 a 4 2 2, 6 4 2, 8 6 2,…<br />
<strong>The</strong> difference between each pair of consecutive even<br />
numbers is 2. <strong>The</strong>refore if the nth even number is 2n,<br />
the next even number must be 2n 2.<br />
b 2n (2n 2) (2n 4) 6n 6 6(n 1), which<br />
must be a multiple of 6<br />
9 (3n 1) 2 (3n 1) 2 (9n 2 6n 1) (9n 2 6n 1)<br />
12n 4 3n, which must be a multiple of 4<br />
16(2x 1)<br />
10 _________<br />
x(x 1)<br />
Chapter 33 <strong>Answers</strong><br />
33.1 Get Ready<br />
1 (2, 2)<br />
Exercise 33A<br />
1<br />
a b c d B e D<br />
a<br />
b<br />
c<br />
A<br />
C<br />
2 a i ( 5 6) ii ( 12) iii ( 4 6)<br />
3 a<br />
b <strong>The</strong>y add up to ( 0 0) .<br />
A<br />
B<br />
b ( 9 3)<br />
c trapezium<br />
d <strong>The</strong>y are parallel and the length of AD is 3 times the<br />
length of BC.<br />
4 a y<br />
A<br />
D<br />
B<br />
C<br />
O<br />
x<br />
b i (0)<br />
4 ii ( 2<br />
3)<br />
c i <strong>The</strong>y are the same.<br />
ii <strong>The</strong>y are parallel with the same length, but in opposite<br />
directions.<br />
5 a and c, b and h, d and g<br />
33.2 Get Ready<br />
1 a 25 b 9.43<br />
Exercise 33B<br />
1 a 13 b 13<br />
e 17 f 4 √ __<br />
5<br />
c √ __<br />
10 d √ __<br />
74<br />
2 a 25<br />
b length AC √ ________<br />
(7 2 24 2 ) 25, so AB AC and the<br />
triangle is isosceles.<br />
3 rhombus<br />
33.3 Get Ready<br />
y<br />
4<br />
3<br />
2<br />
1<br />
A<br />
1 O 1 2<br />
1<br />
C<br />
Translation by ( 1 2)<br />
B<br />
3 4<br />
x<br />
C<br />
D<br />
708<br />
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<strong>Answers</strong><br />
Exercise 33C<br />
1<br />
d<br />
a b<br />
a<br />
b<br />
a<br />
b<br />
2 a<br />
b<br />
1<br />
2 p<br />
a b<br />
2 a ( 6 8) b ( 4 8) c ( 2 4) d (<br />
9<br />
5) e ( 8<br />
3)<br />
3 (<br />
5)<br />
10<br />
4 a i ( 4 3) ii ( 4 3) b <strong>The</strong>y are the same.<br />
c i (<br />
10) 8 ii (<br />
10) 8<br />
___ ›<br />
___ ›<br />
d <strong>The</strong>y are the same.<br />
5 a ED is parallel to AB , in the same direction and has the<br />
same length.<br />
b i n m ii n m p c n m<br />
33.4 Get Ready<br />
1 a (<br />
10) 6<br />
b ( 9<br />
3) c (0)<br />
0<br />
Exercise 33D<br />
1 a<br />
c<br />
b<br />
a<br />
b<br />
b<br />
2p<br />
3 a i (15) 20 ii ( 12 iii<br />
6) ( 10<br />
b i 5 ii 10<br />
4 a ( 2 b i<br />
5<br />
5) (<br />
iv<br />
30) ( 26<br />
48)<br />
ii<br />
20<br />
4) (<br />
16)<br />
c <strong>The</strong>y are parallel and the length of RS is 4 times the<br />
length of PQ.<br />
5 (16, 8)<br />
6 a b a b midpoint of OB<br />
___ › ___ › ___ ›<br />
7 a AB , EF and GH<br />
b i 5p 3q ii 6m 14n<br />
8 a 2m b 2m n c m x d x m n<br />
33.5 Get Ready<br />
1 a<br />
7<br />
(<br />
7) b ( 8<br />
5) c ( 15 2)<br />
Exercise 33E<br />
1 a i ( 3 9) ii ( 9<br />
27)<br />
b ABC is a straight line such that the length of AC is 3<br />
times the length of AB.<br />
2 a b a b<br />
1_<br />
2 (b a) c 1_ (a b)<br />
2<br />
3 a<br />
1_<br />
2 (a b) b a b c 1_ (a b)<br />
2<br />
d <strong>The</strong>y are the same point.<br />
e <strong>The</strong> diagonals of a parallelogram bisect each other.<br />
4 a trapezium b n 2m k<br />
5 a i b a ii 1_<br />
4<br />
1_<br />
b iii a b iv<br />
1_<br />
4 4 a b<br />
v 3_ (b a)<br />
4<br />
b EF and AB are parallel. <strong>The</strong> length of EF is 3_<br />
6 a i 1_<br />
2<br />
times the<br />
4<br />
length of AB.<br />
3_<br />
(m n) ii (m n) iii<br />
1_<br />
(3n m)<br />
4<br />
b 3n m<br />
c MQ and MR are parallel with the point M in common, so<br />
MQ and MR are part of the same straight line.<br />
MR ____<br />
MQ 4<br />
4<br />
709<br />
Z01_EMHA_SB_GCSE_0839_ANS.indd 709<br />
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<strong>Answers</strong><br />
7 a 2b b 2a b c 4a 2b 2(2a b)<br />
d S is the midpoint of OT.<br />
e 30<br />
Review exercise<br />
1<br />
P<br />
2 a (4, 5) b ( 3 c 5<br />
4)<br />
3 a b ___ a<br />
›<br />
b AP 3_ (b a)<br />
___ 5<br />
› ___ › ___ ›<br />
OP OA AP a 3_<br />
1_<br />
( b a) (2a 3b)<br />
5 5<br />
4 a 2(a b)<br />
b 7a 6b<br />
5 a i (<br />
3) 4 ii 5<br />
b ( 3 7) c (7, 4)<br />
6 a 2(a ___ 2c)<br />
›<br />
b OM 6c 3a 3(a 2c) 3_ ___ ›<br />
OP<br />
2<br />
OP and OM are parallel with the point O in common, so<br />
OP and OM are part of the same straight line.<br />
7 a a ___ b<br />
› ___ › ___ › ___ ›<br />
b FE FC CD DE a b a b 2a<br />
So FE is parallel to CD.<br />
c 2a 1_<br />
___ 2 b<br />
›<br />
d FX 4_ 1_ 8_<br />
(2a b) <br />
5 2 5 a 2_<br />
___ 5 b<br />
›<br />
CX ( 8_<br />
5 a 2_<br />
3_<br />
b) (a b) <br />
___ 5 5 ( a b)<br />
›<br />
CE a b<br />
CX and CE are parallel with the point C in common, so<br />
CX and CE are part of the same straight line.<br />
8 a i 5p ii 2q iii 4p q<br />
b 3p 2q<br />
9 a<br />
1_ (p q)<br />
___ 2 › ___ › ___ ›<br />
b RS OR OS 1_<br />
2 p 1_<br />
1_<br />
( p q) <br />
2 2 q<br />
So RS is parallel to OQ.<br />
10 a 2a ___ 2b<br />
›<br />
b QR 2a 2b 6a 4a 2b<br />
___ ›<br />
XY 1_ ___ › ___ ›<br />
MN MQ 1_ ___ ›<br />
QR 1_<br />
2 2 2 ( 2 a 2b) a<br />
1_ (4a 2b) 2a<br />
2<br />
So XY is parallel to OR.<br />
11 a ___ a b<br />
›<br />
b AX 2(a b)<br />
___ › ___ › ___ ›<br />
DX AD AX 2b 2(a b) 2a<br />
So AB is parallel to DX.<br />
710<br />
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