Page 227 - Maths Skills - 8
P. 227
Answers 225
(v) 960 ends at odd number of zeros. It is not a perfect square. (vi) 7928 ends at 8. It is not a perfect square.
2. (iii), (v) 3. (i) 16 (ii) 121 4. (i) (8, 15, 17) (ii) (16, 63, 65) (iii) (24, 143, 145)
(iv) (42, 440, 442) 5. (i) 481 (ii) 1273 (iii) 161 (iv) 213
6. (i) 1+3+5+7+9+11+13+15+17+19+21+23+25+27+29+31+33+35+37+39+41+43+45+47+49+51+53
(ii) 1+3+5+7+9+11+13+15+17+19+21+23+25+27+29+31+33+35 (iii) 1+3+5+7+9+11+13+15+17+19+21+23+25
(iv) 1+3+5+7+9+11+13+15+17+19+21
7. (i) 214 (ii) 600 (iii) 74 8. (i) 220, 221 (ii) 180, 181 (iii) 420, 421 (iv) 264, 265
9. (i) 11² = 121 (ii) 11² = 121
101² = 10201 101² = 10201
1001² = 1002001 10101² = 102030201
10001² = 100020001 1010101² = 1020304030201
100001² = 10000200001 101010101² = 10203040504030201
1000001² = 1000002000001
10000001² = 100000020000001
Exercise - 3.2
1. (i) 576 (ii) 4761 (iii) 1369 (iv) 33489 (v) 531441 2. (i) 1089 (ii) 45796 (iii) 8649 (iv) 30625 (v) 108241
3. (i) 7225 (ii) 22500 (iii) 2401 (iv) 1089 (v) 10201
Exercise - 3.3
1. (i) 27 (ii) 60 (iii) 45 (iv) 96 (v) 121 (vi) 63 (vii) 207 (viii) 128 (ix) 132 (x) 196
2. (i) 3; 81 (ii) 11; 77 (iii) 2; 56 (iv) 5; 75 (v) 3; 30 3. ` 47700 4. (i) 3; 14 (ii) 6; 29 (iii) 5; 62
(iv) 7; 41 (v) 13; 17 5. ` 750 and 750 donors 6. 6728 m 7. 1764 8. 32400
2
9
Exercise - 3.4
1. (i) 67 (ii) 89 (iii) 113 (iv) 29 (v) 119 (vi) 217 (vii) 120 (viii) 73
(ix) 147 (x) 134 (xi) 304 (xii) 212 2. 39 3. 104 4. 89 5. 132
6. 100; 10 7. 99856 8. 99; 19 9. 88 cm; 168 cm
Exercise - 3.5
1. (i) 3.7 (ii) 0.77 (iii) 3.17 (iv) 1.23 (v) 0.43 (vi) 9.3 (vii) 1.04 (viii) 3.52 2. 2.64 3. 1.949
4. 0.94 5. (i) 1005.75 (ii) 83.636 (iii) 439.50 (iv) 1.461 6. (i) 9 (ii) 1 13 (iii) 468 (iv) 2 1 (v) 627
23 17 18
(vi) 13 7. 3.6 m 8. 181.20 m 9. 2.431 10. 987; 8.883
17
Assessment Time
A. 1. (b) 2. (b) 3. (b) 4. (d) 5. (b) B. 1. a rational number 2. perfect square 3. odd
4. Pythagorean triplet 5. m C. 1. F 2. F 3. T D. 1. x = 62 2. x = 72 3. x = 76 4. 210
E. 1. (a) 2. (a) 3. (d) F. 1. 9 & 324 2. 550 3. 14 4. 68 m 5. 5 cm G. v = u + 2 a.s
2
2
HOTS
1. 576 2. 650 m 3. 30 m 4. 84 m 5. 24 plants 6. 16 children
Assessment - 1
1. (iii) 2. (i) 3. (ii) 4. (iv) 5. (iii) 6. (iii) 7. 1.3879 × 10 8. 1 9. 90
3
10. sum 11. –1 12. True 13. False 14. False 15. True 16. True 17. (i) 616 cm (ii) 3 slices (iii) 23
2
–7 –6 –5 8
18. A 19. A 20. 4 21. 2 22. 32 32 32 23. 58 24. 5 25. 7,76 26. 3
,
,
9
27. 3 28.
12
