Page 182 - Revised Maths Wisdom Class - 6

180 MATHS

REVIEW TIME

A. 1. – 1 2. 4 3. 0 4. 19 6. 9 7. 8 km below sea level 8. No B. 1. (c) 2. (b) 3. (b) 4. (c) 5. (d)
6. (b) 7. (c) 8. (c) 9. (a) C. 1. – 7 2. – 29 3. 331 4. – 2 5. – 116 D. 1. F 2. T
3. F 4. T 5. F E. 1. (b) 2. (c) 3. (c) 4. (a) F. 1. (b) 2. (a) 3. (b)
G. 1. Saturn 2. E 3. – 1 4. (a) – 272° C, – 249° C, – 201° C, – 157° C, – 101° C (b) less than 5
Integrated Question
333, 867, 59, –85, –166, –220, –320, –330
Practice Paper - 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. b 17. c 18. b
19. c 20. c 21. a 22. –190 23. 1, 2, 3, 6 24. 77 25. 77, 90

26. 27. profi t ` 45 28. –193 29. 20, 40, 60

Chapter-3 : Prime Time

Exercise – 3A
1. (a) 11, 22, 33, 44, 55 (b) 37, 74, 111, 148, 185 (c) 16, 32, 48, 64, 80 (d) 43, 86, 129, 172, 215 (e) 87, 174, 261, 348, 435
2. (a) 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60 (b) 1, 5, 17, 85 (c) 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 96 (d) 1, 5, 7, 25, 35, 175
(e) 1, 2, 3, 4, 6, 12, 23, 46, 69, 92, 138, 276 3. 35, 70 4. (a) 12, 24, 36 (b) 12, 24, 36 (c) 33, 66, 99
5. (a) 1, 5 (b) 1, 3, 9 (c) 1, 2 6. 72, 75, 78, 81, 84, 87, 90
7. (1, 60) (2, 30), (3, 20), (4, 15), (5, 12), (6, 10), (10, 6), (12, 5), (15, 4), (20, 3), (30, 2), (60, 1) 8. not a perfect number
Exercise – 3B

1. Prime numbers: 29, 31, 37, 41, 43, 47, 53 and 59
Composite numbers: 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58
2. 7 3. (a) 67 + 5 (b) 29 + 37 (c) 11 + 29 (d) 23 + 29 4. (a) 41 + 43 (b) 59 + 61 5. (3, 7), (16, 25), (2, 3), (5, 7)
6. 90, 91, 92, 93, 94, 95, 96 7. No, It will always have 5 as a factor other than 1 and the number itself
8. (3, 5), (5, 7), (5, 11), (3, 13), (7, 13) 9. (a) 3 + 29 + 31 = 63 (b) 5 + 43 + 47 = 95 (c) 7 + 19 + 23 = 49
10. (a) Not correct, as 2 is even prime number. (b) Not correct as 1 is neither prime nor composite.
(c) correct, as multiples and primes are factors of the product. 11. (a) 12. 13 + 31 13. 2 × 2 × 2 × 2 × 2 × 3 14. 12, 24, 36, 48, 60, 72, 84, 96
15. (a) False (b) False (c) False 16. 21, 24, 25; 22, 23, 25; 21, 22, 27 and many more 17. 45
Exercise – 3C
1. (a) 63 (b) 312 (c) 89 (d) 95

3 × 21 2 × 156 1 × 89 5 × 19

3 × 3 × 7 2 × 2 × 78
2 × 2 × 2 × 39

2 × 2 × 2 × 3 × 13

2. (a) 1000 = 2 × 2 × 2 × 5 × 5 × 5 (b) 234 = 2 × 3 × 3 × 13 (c) 834 = 2 × 3 × 139 (d) 194 = 2 × 97 (e) 377 = 13 × 29 3. 998, 2 × 499
4. 150 150 150 150

2 × 75 6 × 25 3 × 50 5 × 30

2 × 3 × 25 2 × 3 × 5 × 5 3 × 2 × 25 10 × 3
2 × 3 × 5 × 5 3 × 2 × 5 × 5 2 × 5