Page 232 - Maths Skills - 8

230 Maths

B. 1. S.I. 2. transportation, labour charges, taxes, maintenance 3. Principal 4. interest 5. marked price
 R  n
6. Principal 7. 1+ 100  8. R % 9. time 10. R %


2
4
C. 1. F 2. F 3. T 4. T 5. T 6. F 7. T 8. T 9. F
D. (a) ` 8800 (b) ` 800 (c) ` 1120 (d) ` 11500 E. 1. (a) 2. (d)
3
F. 1. ` 18000, 20% 2. A = ` 14185.19, C.I. = ` 4185.19 3. ` 25158.95 G. (a) (b) 60
10
(c) yes, there is an increment (20 students) increase = 12.5% (d) Foot ball =72, Chess = 144, Cricket = 180, hockey =60
HOTS
1. ` 8000, 5% p.a 2. ` 11000

Chapter - 9: Direct and Inverse Proportions

Boot-up
A. 1. (i) 2. (ii) 3. (iii) 4. (ii) 5. (i) B. 1. 6 2. 60:1 3. 30 4. increase
C. 1. T 2. F 3. F 4. F 5. T 6. F
Exercise - 9.1

p 1.5 3 4.5 18 22.5 2. (i) and (ii) 3. 1800 sheets
1. (i) 4. 624 $ 5. 1 hour 8 minutes
q 2 4 6 24 30
6. 3 hours 45 minutes
p 7 9 11 15 19 7. ` 400 8. 25 days
(ii) 9. ` 400 10. 275 km
q 28 36 44 60 76
11. 26 days 12. 56.25 metres
9
p 20 25 10 40 30 13. 48 men 14. 1.1 × 10 pounds
(iii)
q 8 10 4 16 12

Exercise - 9.2

p 9 3 12 4 2 2. (i) and (iii) 3. 684 cm 3
1. (i) 4. 25 men 5. 1200 workers
q 8 24 6 18 36
6. 75 cows 7. 13 hours 30 minutes
p 12 3 6 15 24 8. 10 days 9. 5 days
(ii) 10. 30 days 11. 4 days
q 10 40 20 8 5
12. 12 hours

Exercise - 9.3

1. 2 2 days 2. 135 garlands 3. 21 1 days 4. A = 27 days, B = 54 days 5. 2 8 days 6. 4 2 days 7. 1 1 days
3 9 11 19 6
8. 30 days

Exercise - 9.4

1
1. 4 or 1 hours 2. 6 hours 3. 40 hours 4. 160 minutes 5. 20 hours 6. 2 11 hours
3 3 12
Exercise - 9.5

1. (i) 90 km/h (ii) 216 km/h (iii) 162 km/h (iv) 234 km/h 2. (i) 2.5 m/s (ii) 10 m/s (iii) 25 m/s (iv) 40 m/s
3. 2 minutes 4. 320 m 5. 225 m 6. 60.3 km/h ; 32 seconds 7. 250000 m 8. 42 minutes 9. 332 m/s
10. 18 seconds 11. 18.75 km/h 12. 9 km 13. 2376 km 14. 30 km/h 15. 28 seconds 16. 30 seconds 17. 1800 km
18. 1 minute 30 seconds