Edexcel Maths Answer Key, Exams of Mathematics

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Edexcel Maths Answer Key by abdo123456 | Edexcel IGCSE Maths 1 Answers to activities and exercises Unit 1 1NUMBER 11 EXERCISE 1 16 2313 Zar 233,75%4 110.15, 15% 163 21 14116 12 0.075, 7.5% 17 3 22 25417 1419 EXERCISE 1* 161116 273823340 27 12 2334045 3813 31811549 4914 7115638 51015 1256740 17 680 22 3.1 27 41.86 18 910 23 24 28 49.88 19 0.765 24 18 20 0.095 25 26.25 21 39 26 42.84 EXERCISE 2 1611165-20-6 327 12 17-8 -3-6 10 38 13 18 13-10 -24 4-17 9-12 14-55 13 10 28 153 EXERCISE 2* 1-2610 1112 16 74267 18 12 1817 144 3 23 8 10 13 36 18 19645912 14135181022 3 15 49 EXERCISE 3 11.86 12.6 litres 11 15% 2 0.272 km 7 £31.80 12 6% 3 5.52 m 8 £64.80 13 10% 4 1.38 cm 9 £45.50 14 15% 5 0.684 10 £71.20 15 5% IGCSE Maths Answers — Unit 1 4 1318, 20%57, 35% 132051827 49 231,0.2543,375%873 16 5.94 m 18 $9120 17 Percentage increase in value = 19 688 20 468 7800 100 = 6% 60 80 = 2.70% increase. = 3.95% increase. 80 2000 EXERCISE 3* 10.75 6 106.25 11 15% IGCSE Maths Answers — Unit 1 2 21 kg 7 68.005 km 12 $836 3 $171 8 86.1 kg 4 11.7 km 9 $80.04 5 52.5 10 $89.18 4.25 34 13 Profit = 4.25; percentage profit = 100 = 12.5% 14 39% 15 0.0402% 16 33.3% 17 250% 18 11.1%; 12.5% 19 There are 500 million telephones in the world, 60 000 in Ethiopia. Population of Ethiopia is 30 million. 20 1976 1986 1996 Largest tin (p/g) Smallest tin (p/g) 0.0359 0.0493 0.0607 0.1 0.0738 0.16 % increase in cost '86—96 21.6 60 % increase in cost ’76—'86 Largest tin Smallest tin 69.1 102.8 Inflation was much higher between 1976 and 1986. If the larger tin were bought in 1976 you would get 37.3% more for your money. In 1986 you would get 64.7% more for your money and in 1996 you would get 117% more. ACTIVITY 1 Neurons: 1011 Connections: 1015 Connections per second = 1015 = (60 60 24 365 75) half a million EXERCISE 4 16 11 16 21 26 31 36 105 107 103 102 5.68 102 56 000 7 970 000 1.4 102 2 7 12 17 22 27 32 37 105 1013 102 4.56 102 3.84 101 4 090 000 987 600 5 10 3 8 13 18 23 28 33 1010 1011 103 6.78 101 7.0605 102 678 900 1000 4 9 14 19 24 29 34 1010 102 108 1.2345 102 1.23 108 560 10 000 5 10 15 20 25 30 35 103 105 101 6.7 107 4000 65 000 8.4 109 EXERCISE 4* 1611162125 2 4.5089 104 2 8.705 104 3 2.983 107 4 7.654 107 5 103650 217 108100r19 10 10 108 10 12 106 13 6.16 106 14 2.7 108 15 4 10 100 or 1 4 16 42 4 7.083 10 17 9.1125 10 18 2.43 10 19 2.5 10 20 3.46 108 9.653 108 22 4 103 23 1010 24 1000 Saturn 10 cm, Andromeda Galaxy 1 million km, Quasar 1000 million km 100 = 5% REVISION EXERCISE 6* " 14 37 512 48.19 102 103 5 8.10 10 108 103 6 0.0456 7 45 600 8 1012 8 7 12 5.28 10 13 8 102 11 1.586 10 14 To increase 80 by 10% = 88. To decrease 120 by 30% = 84. the first by 4. 15 Profit = 162 000; percentage profit = 162 000 900 000 100 = 18% 16 0.04 13.50 = 0.54; 13.5 — 0.54 = 12.96 17 $42 928.40 18 2 cents loss 1ALGEBRA 11 ACTIVITY 2 3 6, half number added. INVESTIGATE Substituting any value of x gives the same values for both expressions because x3 + x2+x+1 = (x + 1)(x2 + 1). IGCSE Maths Answers — Unit 1 3 EXERCISE 7 16 11 16 21 4ab —3xy 2cd 2ab + 3bc —3p2 — 2p 2 7 12 17 22 3uv y — xy ab 0 p3 + 7p2 38 13 18 23 7xy a— ab —4xy 0 5x2y — 3xy2 4 9 14 19 24 Bab 2 — 6x —3pq 2gh — S5jk + 7 3ab3 — 2ab2 5 10 15 20 —3pq —3y — 4 2ab + Sbc 3ab — 3bc + 2 EXERCISE 7* IGCSE Maths Answers — Unit 1 16 11 16 21 24 —xy 2 -2xy 4xy 7 0 2 12 2r4 3q x5 — 7x3 + 217 h3+ h2+ 3h + 4 a2b3c - 0.6a3b2c + 0.3 4f 2g2h2 + OF 2g2h3 - 2f 2g3h2 3 8 13 18 22 4ab—bO x+#1 2h3 - 2h2 + 2049 14 19 23 11xy —x 5 6ab 3ab + 3bc 10 2fg + 11gh x4 + 3.15 a3+ 2a2 + a 7a2b — 3ab 20 3fg — 3fg2 — 5g2f 2524 4pqr—2pqr EXERCISE 8 16 11 16 6a 2a4 4rs2 2413 2 7 12 17 28x 15a5 3de3 12x3 3 8 13 18 2x2 8b6 2a2b2 3y5 4 9 14 19 3y2 6st Qu2v2 20a3 5 10 15 20 3x3 20rt 4y3 27b3 EXERCISE 8* 16 11 16 8a3 30b7 30a3b3c5 9x2y5 2 7 12 17 3x4 18y3 24a2b5c6 3x3y4 — 2x3y2 38 13 18 15x4y2 4 8xy6 4 32a 9 36x5y3 S6xy4 14 135x4y 6 25 2 Sx y + 3x y 19 14a4b6 5 10 15 20 Ga7 24x4y7 10x3y3 2x6y5 EXERCISE 9 161116 10 + 15a —27g — 45 5a + 4b 10a — 2b 27 1217 12+ 21x 4x- 12 7x + 2y 1.4x + 0.3y 3.8 13 18 2b — 8c 7y — 28 3t— 18 0.5b 49 14 19 Gv — 30w 5 -Ga — 24 2b —a 10 Sy — x SV—-17 15 6x +y2.1a—11.7 204.3t+9.1 EXERCISE 9* 1591317 12m—8 2 10n— 30 15a + 5b — 20c 6 15a — 6b — 9c 3y — x 10 x + 12y -6x — 3y 14- 8q -0.6a - 4.2b + 0.7 18 0.3a-0.1b-0.1¢3 7 11 15 19 2x —2y + 2z 2x - 3y +4-1.4x-2.2 4.6x — 6.2y — 0.4z -0.44x2 - 3.8xy — 1.2y2 48 12 16 20 3a + 3b — 3c 5x + 3y—4-1.1-1.6z 0.8x + 1.8y — 0.4z a2 — 0.61ab — 1.1b2 EXERCISE 10 146391115 4 2127 100 12-33 315 8 108 13 2.4 4-33 912 146.5 16 19.5 21 0.985 17 26.6 22 -10.1 18 21.6 236.8 191.4 20 -4.8 EXERCISE 10* 199.9 6 4.59 11 38.8 2 -133 7 580 3 5.13 8 32.4 4 10.7 9 8.49 5 40.7 10 0.0468 EXERCISE 11 IGCSE Maths Answers — Unit 1 5 1x=36x=-211x=116x=121x= 5927 2x=4 7 x=212x=617x=-222x= 58 3x=-18x=4 13 x=-618x=-123x= 43 4x=-39 x=8 14x =-1019x= 23 5x =-210x=915x=120x= 15 24x=1 25x=-1 26 x=— 27 238, 23931b=4 28 72, 73, 74 32 b= 2.4 29 x = 10; 40, 80, 60 33 -15 340.5 30 x = 25; 75, 50, 55 EXERCISE 11* 16 11 16 x=4 x=2 x=5 123, 125, 127, 129 27 1217 x=3 x =-5 x=2 11, 44, 67 kg 381318 x= 11x=-4x=0 1449 1419x=10x=-4x=1 x =-502km3 5x=-2 10x =-6 15 72, 74, 76 20x=2.5 21 45 m (2 sig figs) 22 4,20 cm 23) 1 EXERCISE 12 1x=16x=311x=-116x=- 1 2x=47x=-312x=-217x=2, 38 3 x=2 8x =-213x=018x=2, 16 4x=5 9 x=114x=0199 5 x=4 10x=215x=- 2013 12 EXERCISE 12* 1 x=4 6 x= 11 16 18 20 22 25 2 x=3 7 x= 45 EXERCISE 13 1X = 13 6 x=6 2 x=4 7 x=4 3 x=3 8 x=4 4 x=7 9 x=... 52 5 x=210x=— 53 EXERCISE 13* 1 x=8 IGCSE Maths Answers — Unit 1 6 x=3 11 6 hits 2 x=5 7 x=9 12 15 3 x=5 8 x=5 13 4 4 x=1 9x=34 5. x=4 10 x= 35 REVISION EXERCISE 14 161114 3x-22 2a47x=4.812a4x+ 12 =54 ab 4a4 x=2 b 10.5, 16.53 8 13 c 6a —Sa — 4ab 145, 146, 147 18 mph 4 2a29x+7y5a310x=7 REVISION EXERCISE 14* 1 4xy2 — 3x2y 6 x = 1.25 11 11 years old 2 2x3y3 7 x = -6 12 6 m/s 3 1 8 x=2 13 $98 4 2x3y + xy3 + x4 9 x=4 5 x = 20 10 72 m2 1GRAPHS 11 INVESTIGATE Gradient of AB = 0.1 Closer to zero. Gradient AC = 0 Larger and larger. Gradient BC is infinite. EXERCISE 15 11621110m162m721 14 30.58 13 40.59- 14 5310-1 15 2.325 mb 159m 1245m17a14m 131.5m 1b30 14 10 km 18 a-2 EXERCISE 15* 4 381cm6 54 67 552 10No 14q= 10.4 6511a 7 Yes b0.1cm 8 No 12 26m 9 Yes 13 p=-2 15 y = 3x-220y=-x-1 18y=-0.2x-519y=2x+4 21 y=-5x- 1 22 y = 3x 23 For example a y=x—1 b y=— x+2 12 y=1 24b9°C ct=0.6m + 9d 35 min e 117 °C, no, over boiling point, 0 t 30 seems sensible. EXERCISE 16* 1242,6332511-,-33 15, 34376,-23512-,44 2-4,- 30,-8 3452.43 40,25914y=-x+6.3 19a 7x + by =84 13 y=2.5x-2.3 18 y=8x+84cy= 1x-12 1S y= 16 y = -0.7x — 3.3 21 For example a x=2 22 b d h= 1t-0.653 17y=2.5x-35b2x+y=2 20 9x — 5y = 96 c—0.32 m, no, t>2eh= 2t-73 302 h, i.e. 2am on 14th April 2t-7givest3 Beanstalk is 6.7 m at noon on 2 April. Has to grow another 93.3 m. 93.3 = 150 hours 6 days 6 h ie. at 6 pm on 8 April. 4 Gradient of BC = gradient of AD = -5b=+41.56 3y=x+67aF=20P + 20;S=35P + 35d 10.25 pounds 8 b 35h + 3t = 105 d —2.14 m, Not sensible, Ot 56 35 cece 3h 48 min; 2 h 40 min about 1.15 pm 11.7 s 28 s, assume continues linear. 1SHAPE AND SPACE 11 ACTIVITY 6 IGCSE Maths Answers — Unit 1 2 a = 34°, b = 146° 6 a = 36°, b = 72° 10a = 50° 14a =55°, b= 15° 18 12 sides 3. a = 65° 7 a= 57°, b= 123° 11 a= 124°, b = 56° 15 45°, 135°, 1080° 19 x = 74°; 74° and 148 4 a= 37° 8a= 44°, b = 112° 12 a = 42°, b = 138° 16 900°, 128 ° 20 15, 2340° 47 EXERCISE 19 1a=102°,b= 78° 5a=73°, b= 34° 9a=31°, b= 31° 13 a= 58°, b = 32° 17 9 sides EXERCISE 19* 15913 a= 137°, b= 43° a=17° x= 50° a= 40", b= 113° 26 10 14a = 153°, b= 27°, c= 63° a= 39° x = 36° a= 56°, b = 38° 37 11 15a = 36° 180° — 2x a = 56°, b = 34° 20 sides 4 8 12 16 a= 20° 100° - y a= 73° 6 sides EXERCISE 20 15.86 cm 2 3.62 cm 3 4.2 cm, 14.7 cm2 5 c PS = QS = RS = 4.7 cm; all equal, ona circumcircle 6 5.3 cm 7 8 4 JK=9.2 cm, JM=6.7 cm