Page 323 - ICSE Math 8

Exercise 21.4 4. ` 528 5. (a) 110 m (b) 1.75 m 6. 1,500 7. 5 : 4
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1. 91 cm 2. 87.5 cm 3. (a) 448 cm (b) 54 cm 2 8. 1,760 cm 9. 7,755 cm 10. (a) 968 cm
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4. 486 cm 2 (b) 1,161.6 cm (c) 2,140.66 cm 11. ` 63.53
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Exercise 21.5 Exercise 22.4
1. 132 cm 2. 24.64 m 3. 28 m; 2,464 m 1. 0.176 m 2. 275 L 3. ` 844.80 4. 4.2 cm
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4. 14 cm; 88 cm 5. 24 m 6. 8.8 m; 15 7. 7 : 6 5. 7 cm, 2,464 cm 6. 4,710 cm 7. 1,056 m , 4 m
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8. 10.5 cm 9. 367.38 cm 2 8. 5 : 3 9.1,33,056 cm 10. 1 : 4
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10. 616 11. 4,290 m 12. 3,014 m 13. 23.76 km/h Mental Maths
14. (a) 6.86 cm (b) 113.04 cm (c) 43.96 cm 15. 536 cm 2 1. (a) (iv) (b) (i) (c) (ii) (d) (ii) (e) (ii) (f) (ii)
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Mental Maths 2. (a) True (b) True (c) False (d) False (e) True
1. (a) 60 cm (b) 44 m (c) 22 cm (d) π 3. (a) space (b) 1 (c) co-axial, radii
2. (a) True (b) False (c) True (d) False (e) True (d) 1,000; 10,00,000 (e) 144 m 3
Practice Time
Practice Time 1. 80,000 2. 36 3. 90 m × 75 m × 60 m
1. 154 cm 2. 432 cm 3. 750 4. 190 cm 2 4. 89,760 cm 5. 2,079 cm 6. 2 : 3
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5. 2,500 6. 7 cm 7. 28 cm; 14 cm 7. C : C = 2 : 5 and V : V = 4 : 25, where C and C
17 are curved surface areas and V and V are volumes of
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8. (a) 88 cm (b) 616 cm 9. 6 m; 18 m 10. 4,686 m 2 two cylinders respectively. 1 2
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11. (a) 249 cm (b) 1354.5 cm 12. (a) 132 cm (b) 29 cm 2 8. 286 cm 9. 0.512 m , 0.8 m
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13. 45.5 cm 2 10. 10,560 cm , 88.704 kg 11. 8,333 (approx.)
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Think Smart 12. 6 m 14. 60 cm
1. (a) 2. 1050 m 2 Think Smart
1. 19 m approx. 2. 121 people
Chapter 22
Chapter 23
Exercise 22.1
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1. (a) 1,440 cm (b) 8.32 m 2. (a) 250.047 cm Exercise 23.1
2. (b) 30 (c) 2 (d) 28 (e) 7 (f) 6
(b) 373.248 dm (c) 125 m 3. 0.975 m or 975 L 3. (a) 3 (b) 12 (c) 6 6. (a) 25.6 mm (b) 2
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4. The volume will change to th of the original volume.
8 Exercise 23.2
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5. 1.5 × 10 m 6. 1,096 dm 7. 7,315 L 8. 2.5 cm 1. (a) 50 (b) 5 (c) 60 (d) 47.5 and 57.5 (e) 5
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9. 216 10. 32 11. 8 : 1 12. 750 13. 36 cm Exercise 23.3
14. ` 2,620 1. (a) This bar graph gives the information about the
marks obtained by a student in two consecutive
Exercise 22.2 years namely 2006–2007 and 2007–2008 in various
1. 57.24 m , 34.84 m 2. 13.42 cm subjects.
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3. (a) 121.5 cm , 81 cm , 7.79 cm (b) Maths (c) English (d) Hindi (e) 5
(b) 61.44 m , 40.96 m , 5.54 m 4. (a) 210 (b) Bus (c) Scooter (d) 5 : 8 (e) 60%
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(c) 864 dm , 576 dm , 20.78 dm Exercise 23.4
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(d) 13.5 dm , 9 dm , 2.60 dm 4. (a) In school canteen (b) (c) 25% (d) 3:1
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4. (a) 384 m (b) 96 dm (c) 150 cm (d) 216 m 2 5. (a) ` 6 crores (b) company V (c) ` 20 crores
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5. (a) 27 cm (b) 343 m (c) 512 dm (d) 729 cm 3 Mental Maths
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6. 896 cm 7. ` 70.78 8. 64 : 125 9. ` 3,600 1. (a) (ii) (b) (iii) (c) (iv) (d) (i) (e) (iv) (f) (i)
10. 10 m 11. 9.9 m, 3,920.4 m 12. 3 : 2 2. (a) False (b) True (c) False (d) False (e) True
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13. 10 m × 15 m × 20 m 14. 3,000 15. 200; 44,000 cm 3. (a) tally, frequencies (b) inclusive, exclusive
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16. ` 2,60,000 17. 4 times 18. 175.5 cm 3
(c) minimum, maximum (d) vertically, horizontally
Exercise 22.3 Value of component
1. 616 cm , 924 cm 2. 3,772 cm 3. ` 22,000 (e) Total value of component × 360°
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