Page 225 - Maths Skills - 8

Answers

Chapter - 1: Rational Numbers
Boot-up
1
1
A. 1. (iii) 2. (i) and (iv) 3. (ii) 4. (i) B. 1. zero 2. – 3. – 4. unlimited
C. 1. T 2. F 3. F 4. T 2 2
Exercise - 1.1

1. Do it yourself. 2. (i) −11 < −15 < −4 < 3 < 19 (ii) −6 < −2 << 1 < 4 (iii) −1 < 3 < −6 < 5 < 7 (iv) 2 < 5 < 6 < 8
0
20 28 15 10 30 9 10 7 7 2 4 −5 3 2 4 9 7 9
3. (i) 7 > 16 > − 15 > − 63 >− 3 (ii) 18 6 19 1 13 (iii) −3 > 2 > 1 > −3 > 5 (iv) 9 > 8 > 23 > − 15
13 39 26 65 25 10 60 5 15 −5 5 9 7 −6 3 6 39 26

4. (i) positive (ii) negative (iii) negative (iv) positive 5. (i) 43 (ii) 516 6. −7 > −15
− 51 − 612 5 7

7. (i) – 5 (ii) – 15 (iii) 35 (iv) 35 8. (i) 138 (ii) −133 (iii) 12 (iv) 6
17 201 25 11
Exercise - 1.2

1. (i) −4 (ii) −264 (iii) 22 (iv) 355 (v) 1123 (vi) −7 2. (i) − 22 (ii) 17
65 133 9 391 3885 19 45 55

(iii) 3 (iv) − 41 (v) − 5 (vi) 7 3. Do it yourself. 4. (i) 3 (ii) −64
14 60 24 30 7 63
(iii) 11 (iv) 390 5. (i) −417 (ii) −1519 (iii) 457 6. (i) −4 (ii) −1 (iii) 1
3 19 160 45 231 5 6 − 33
(iv) 0 (v) – 16 (vi) 2 7. Do it yourself. 8. 23 9. −1 10. −98
3 40 30 143
3
11. 7 12. ` 49.50 13. L 14. −45 15. 64 23 sec. 16. 171
18 8 32 33 70
Exercise - 1.3

,
,
,
1. – 1 2. 17 3. 11 21 4. 13 14 15 16 17 (many answers are possible)
,
,
24 2 2 4 36 36 36 36 36
5. – 49 – 48 – 47 , .... – 39 (write any ten) 6. – 29 – 28 – 27 , ...., – 9 (write any twenty) 7. (i) infinite (ii) infinite
,
,
,
,
80 80 80 80 10 10 10 10
Assessment Time
A. 1. (ii) 2. (iii) 3. (iii) 4. (iv) 5. (ii) B. 1. 4 2. positive 3. 11 4. 25 5. 21
14 28 40
C. 1. T 2. T 3. F 4. F 5. F D. 1. 26250 2. 42000 3. 28000 4. Second day
E. 1. (d) 2. (a) F. 1. –35 2. 357 m , ` 12.975 3. 2190 hours 4. 160, 200
2
27 20
25 23 17
G. 1. 2. 3. 250 4.
2 12 24
HOTS
1 1 Distance −28 22
1. 6 m 2. 269 km, 280 km (Hint: Speed = ) 3. 4. Perimeter of square and by m
10 3 Time 75 15
Chapter - 2: Exponents and Powers
Boot-up
12
A. 1. (iv) 2. (ii) 3. (iii) B. 1. – 64 2. a 8 3. b 4. 2 , 4096
4
C. 1. F 2. T 3. F 4. T