Page 167 - Maths Skill - 6

Answers 165

Exercise - 3.4

1. (i) 3502 (ii) 2907 (iii) 945

2 1751 3 969 3 315

17 103 3 323 3 105

17 19 3 35

5 7

3502 = 2 × 17 × 103 2907 = 3 × 3 × 17 × 19 945 = 3 × 3 × 3 × 5 × 7

2. 1 and the prime number itself 3. No
4. (i) 216 = 2 × 2 × 2 × 3 × 3 × 3
(ii) 1729 = 7 × 13 × 19
(iii) 12000 = 2 × 2 × 2 × 2 × 2 × 3 × 5 × 5 × 5
(iv) 1197 = 3 × 3 × 7 × 19
5. 100000 = 2 × 2 × 2 × 2 × 2 × 5 × 5 × 5 × 5 × 5
6. 9999 = 3 × 3 × 11 × 101
Exercise - 3.5

1. (i) 60, 120, 180, ....... (ii) 252, 504, 756, ....... (iii) 24, 48, 72, ....... (iv) 180, 360, 540, .......
2. (i) 1, 2, 3, 6, 9, 18 (ii) 1, 3, 9 (iii) 1, 3 (iv) 1, 3
3. 330, 360 4. 35 5. 45 6. 75, 125, 175 7. 7 and 5

Assessment Time
A. 1. (iii) 2. (i) 3. (iii) 4. (iv) 5. (iii) B. 1. Prime 2. 23, 29 3. 9 4. even
C. 1. False 2. False 3. True 4. False 5. False D. 1. 9872 2. 11304, 11106, 11124 3. 7524 4. Yes
E. 1. (d) 2. (b) 3. (a) F. 1. 65583 and 65637 2. 2
HOTS

1. 129 2. 45 = 210 \ factors are 1, 2, 22, 23, 24, ... 210
3. In any three consecutive numbers, you will always have a multiple of two and three each. Therefore, product of any three consecutive
numbers is always divisible by 6.

Assessment - 1
1. (c) 2. (d) 3. (a) 4. (b) 5. (a) 6. 21 7. 1 8. b + 1 9. 4
10. negative 11. False 12. False 13. True 14. False 15. True 16. c 17. b 18. a
19. c 20. a 21. –190 22. 1, 2, 3, 6 23. 77 24. 77, 90

25. 26. profit ` 45 27. –193 28. 20, 40, 60