Std : 8 1Mental Maths Competition®

Set -1

1. (26 × 19) + (31 × 11) = _____(a) 381 (b) 479

(c) 279 (d) 835

2. (95 × 37) – (17 × 85) = _____(a) 2070 (b) 2170

(c) 2060 (d) 2270

3. (46 × 16) + (3 × 9) + (19 × 16)=_____(a) 1176 (b) 1067

(c) 1076 (d) 1607

4. (65 × 4) + (81 × 3) – (37 × 5)=_____(a) 418 (b) 218

(c) 318 (d) 328

5. (97 × 4) – (42 × 7) + (63 × 5)=_____(a) 409 (b) 381

(c) 509 (d) 315

6. (25% of 280) + (50% of 182) =_____(a) 151 (b) 161

(c) 251 (d) 171

7. (25% of 200) – (15% of 150)=_____(a) 50 (b) 25

(c) 10.75 (d) 27.5

SECTION 1 (Mental Maths Calculation)

8. (50% of 176) + (25% of 320)–(20% of 400 ) = _____(a) 86 (b) 84

(c) 88 (d) 89

9. (half of 396) + (one thirdof 435) = _____(a) 418 (b) 912

(c) 343 (d) 478

10. (one third of 396) – (half of264) = _____(a) 0 (b) 2

(c) 1 (d) –4

11. square of 24 + square 14 =_____(a) 682 (b) 772

(c) 592 (d) 182

12. square of 95 – square 55 =_____(a) 6500 (b) 7000

(c) 7300 (d) 6000

13. square of 10 + square of 16– square of 13 = _____(a) 187 (b) 135

(c) 139 (d) 138

Std : 8 2Mental Maths Competition®

Set -1

14. square of 25 – square root of169 = _____(a) 612 (b) 456

(c) 613 (d) 645

15. square of 29 + cube root of216= _____(a) 841 (b) 847

(c) 349 (d) 727

16. square root of 196 + cubeof 5 = _____(a) 129 (b) 149

(c) 139 (d) 119

17. cube of 2 + square root5625 =(a) 83 (b) 53

(c) 63 (d) 43

18. Sum of all the divisor of 36= _____(a) 94 (b) 91

(c) 92 (d) 85

19. Sum of all the divisor of 26(a) 32 (b) 4

(c) 42 (d) 41

20. Sum of all prime divisors of210(a) 17 (b) 27

(c) 18 (d) 29

21. Select the greatest numberfrom the given operations.(a) 15 × 23 (b) 428 – 376

(c) 27 + 230 (d) 98 × 2

22. Select the smallest numberfrom the given operations.(a) 41 × 7 (b) 490 – 37

(c) 1800 ÷ 60 (d) 7 × 13

23. If 2055 is divided by 20, theremainder is ______(a) 20 (b) 5

(c) 15 (d) 30

24. If 681 is divided by 12, theremainder is ______(a) 9 (b) 3

(c) 7 (d) 12

25. If 343 is divided by 16, theremainder is ______(a) 14 (b) 7

(c) 12 (d) 4

26. If 2075 is divided by 21, theremainder is ______(a) 16 (b) 15

(c) 11 (d) 17

Std : 8 3Mental Maths Competition®

Set -1

27. 3479 × 49 = ______(a) 140741 (b) 140471

(c) 170471 (d) 10471

28. 1078 × 43 = ______(a) 46354 (b) 46374

(c) 46366 (d) 46324

29. 0.25 × 2.5 = ______(a) 6.25 (b) 625

(c) 0.625 (d) 0.0625

30. 5.15 × 3.2 = ______(a) 14.48 (b) 15.48

(c) 12.48 (d) 16.48

31. H.C.F. of 35, 20, 15 is ______(a) 10 (b) 5

(c) 15 (d) 35

32. L.C.M. of 36, 72 and 96 is______(a) 288 (b) 278

(c) 268 (d) 298

33. 3 – 1.298 = ______(a) 0.032 (b) 1.702

(c) 1.102 (d) 0.702

34. 15.85 + 36.76 – 17.32 = ____(a) 34.29 (b) 37.29

(c) 36.29 (d) 35.29

35. 5 71

+4 71

=

(a) 972

(b) 672

(c) 572

(d) 872

36. – 253

= 517

(a) 5 (b) 9/5

(c) 6 (d) 6/5

37. (3.14 × 1.2) + (4.1 × 5.09) =______(a) 24.637 (b) 42.367

(c) 2.4637 (d) 36.367

38. Double of 3465 = ______(a) 6880 (b) 6930

(c) 6746 (d) 6940

39. Half of 4792 = ______(a) 2286 (b) 2316

(c) 2396 (d) 2886

40. The ratio of 60 min to5 hour is ______(a) 1:5 (b) 3:5

(c) 2:5 (d) 4:5

Std : 8 4Mental Maths Competition®

Set -1

SECTION 2(Mental Maths Concepts)

41. 180 × 10 ÷ (3 × 5 )= ______(a) 120 (b) 130

(c) 140 (d) 160

42. 99 – (43 – 111) = ______(a) –167 (b) 67

(c) 167 (d) 176

43. – 7 + = – 15

(a) 8 (b) – 8

(c) 22 (d) – 22

44. (248 – 134) ÷ 19 = ______(a) 5 (b) 3

(c) 9 (d) 6

45. [(15) × (2) + (– 4) × (4)] ÷ (–7)(a) – 2 (b) 3

(c) 5 (d) 2

46. 686490

=

(a) 57

(b) 75

(c) 76

(d) 78

47. Find 7th term in thegiven series.121,144,169, 196, __, ___, ___(a) 400 (b) 289

(c) 225 (d) 324

48. 73

÷ 213

× 79

=

(a) 277

(b) 721

(c) 727

(d) 73

49. 9 × 38 + 7 × 15 = ______

(a) 449 (b) 447

(c) 347 (d) 747

50. 120 × 10 + 250 × 3 = ______(a) 1950 (b) 1850

(c) 1750 (d) 2050

51. 13.39 ÷ 1.3 = ______(a) 5.3 (b) 10.3

(c) 1.3 (d) 3.3

52. 1248 ÷ 1.6 = ______(a) 7.80 (b) 708

(c) 780 (d) 870

53. 45:90 = 30: ______

(a) 60 (b) 120

(c) 80 (d) 90

Std : 8 5Mental Maths Competition®

Set -1

54. If 7 bags of Soyabeen seedscost ` 4235. Find the cost of9 such bags.(a) 4235 (b) 3246

(c) 3226 (d) 5445

55. The perimeter of triangle is75 cm, if one of its side is31 cm. If the other two sideare equal find their lengths.(a) 22 cm (b) 35 cm

(c) 25 cm (d) 20 cm

56. 3y7

= 414

then y =

(a) 21

(b) 25

(c) 23

(d) 27

57. The ratio of 9 meter : 70 cmis ______

(a) 970

(b) 790

(c) 97

(d) 79

58. The ratio of ` 3:50 paise =______(a) 6:1 (b) 1:6

(c) 2:7 (d) 7:2

59. 2t = 5t – 24, t = ______

(a) 7 (b) –8

(c) –7 (d) 8

60. Find the number whose 7%is 14.(a) 400 (b) 200

(c) 500 (d) 650

Std : 8 6Mental Maths Competition®

Set -1

SECTION 3 (Mental Maths Challenge)

61. Raj purchased following items from the supermarket 10 kg attaat `25 per kg; 3 kg dal moong at ` 60.50 per kg, 2 kg dal Udad at` 45.50 per kg and 2 kg sugar at ` 36.25 per kg. How much didhe pay to the cashier, if the cashier gave him ` 95 back?(a) ` 690 (b) ̀ 450 (c) ̀ 460 (d) ̀ 790

62. Find the smallest number which on being divided by 30, 40, 60and 80 leaves 17 as remainder.(a) 223 (b) 230 (c) 257 (d) 235

63. Find the radius of a circle whose circumference is 96 cm.(a) 15.27 cm (b) 14.37 cm (c) 13 cm (d) 12 cm

64. A car travels 880 km in 8 hours. Find the distance covered in5 hours.(a) 750 km (b) 450 km (c) 650 km (d) 550 km

65. In a library there were 5000 books. Out of this 380 books werediscarded what percentage was discarded?(a) 14% (b) 7.6% (c) 8.4% (d) 9.2%

Std : 8 7Mental Maths Competition®

Set -1

66. Pratik bought an old motor cycle for `25000 and spent ` 2000 forits repairs. For how much shall be sale it to earn profit of 12%?(a) ̀ 30240 (b) ̀ 32040 (c) ̀ 30204 (d) ̀ 32004

67. To make 75 dresses 375 m of cloth was used. To make 85dresses how much of the cloth will be required?(a) 550 m (b) 450 m (c)425 m (d) 475 m

68. 3[12.3 + {(6.5 + 23.5) × 3 + (7.8 – 3.2)}] =(a) 335.7 (b) 322.7 (c) 321.7 (d) 320.7

69. In a hostel the consumption of wheat by 210 students in 7month is 4200 kg. Find the wheat required for 70 student in thesame period.(a) 1300 kg (b) 1400 kg (c) 1500 kg (d) 1600 kg

70. The ratio of income to expenditure of Mr.Rahul is 9 : 7.Find his saving if his income is ̀ 36000.(a) ̀ 8000 (b) ̀ 6000 (c) ̀ 7000 (d) ̀ 28000

Std : 8 8Mental Maths Competition®

Set -1

71. Andy borrows a sum of ̀ 24000 from Richa at the rate of 10% p.a.After 1 year 8 months, how much simple interest will he have topay?(a) ` 480 (b) ̀ 400 (c) ̀ 4800 (d) ̀ 4000

72. If x= 2, y = 16, z = 8 and a = 4, find the value of

zxy

– axy

(a) –4 (b) 4 (c) 8 (d) –8

73. Divide 0.0062 by 31.(a) 0.002 (b) 0.0002 (c) 0.02 (d) 2.0

74. The square plot has a side 45 m long. Find the cost of levellingif at ` 9.18 per sq.metre.(a) ̀ 15889.5 (b) ̀ 18859.5 (c) ̀ 1858.95 (d) ̀ 18589.5

75. Simplify : 10.4 ÷ 13 + 0.26 × 10 – 1.2 = ________(a) 2.1 (b) 2.4 (c) 2.2 (d) 22

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Std : 8 9Mental Maths Competition®

Set -1