Mental Maths Class 9.pptx

Mental maths quizz

1. MENTAL MATHS CLASS 9

2. Round 1 Rules- One question per team. Every team will be given 30 seconds to answer. Correct answer will be given 10 points. No negative marking. Questions cannot be passed in this round

3. If ‘+’ means ‘÷’, ‘–’ means ‘×’, ‘÷’ means ‘+’ and ‘×’ means ‘–’, then 320 ÷ 225 + 15 × 15 – 85 = ? 1 A. B. C. D. 180 -940 780 -140

4. If ‘+’ means ‘÷’, ‘–’ means ‘×’, ‘÷’ means ‘+’ and ‘×’ means ‘–’, then 320 ÷ 225 + 15 × 15 – 85 = ? 1 A. B. C. D. 180 -940 780 -140

5. Probability of an event can be ? 2 A. B. C. D. – 0.7 0.6 1.001  

6. Probability of an event can be ? 2 A. B. C. D. – 0.7 0.6 1.001  

7. The ratio of girls: boys in a school is 5:7. If there are 525 girls, how many boys are there? 3 A. B. C. D. 335 435 735 635

8. The ratio of girls: boys in a school is 5:7. If there are 525 girls, how many boys are there? 3 A. B. C. D. 335 435 735 635

9. Find the missing number 2,8,18,32,? 4 A. B. C. D. 62 46 50 60

10. Find the missing number 2,8,18,32,? 4 A. B. C. D. 62 46 50 60

11. AUDIENCE QUESTION

12. AUDIENCE QUESTION 2

13. Round 2 Rules- Two question per team. Every team will be given 45 seconds to answer. Correct answer will be given 10 points. Wrong answer will be given -5 points. You can pass the question to another team. Pass question will be given 5 points. Question will be passed only once.

14. 70 135 39 23 1 Find the wrong term 9, 11, 15, 23, 39, 70, 135

15. 70 135 39 23 1 Find the wrong term 9, 11, 15, 23, 39, 70, 135

16. 11/5 5/11 5/3 3/5 2 If 2x-3y +4x-7y=0, then the value of y/x is:

17. 11/5 5/11 5/3 3/5 2 If 2x-3y +4x-7y=0, then the value of y/x is:

18. 20 0% 250% 150% 160% 3 A is 40% of B. What percentage is B of A?

19. 20 0% 250% 150% 160% 3 A is 40% of B. What percentage is B of A?

20. Decreased by 8% Increased by 8% Decreased by 4% Increased by 4% 4 The price of an item increases by 20% and then decreases by 20%. So the price has:

21. Decreased by 0% Increased by 0% Decreased by 4% Increased by 4% 4 The price of an item increases by 20% and then decreases by 20%. So the price has:

22. 22 20 23 19 5 If 2x+5y=18 and x=2, what is the value of 4x+5y:

23. 22 20 23 19 5 If 2x+5y=18 and x=2, what is the value of 4x+5y:

24. 48 4 36 32 6 A person’s present age is two-­fifth of the age of his mother. After 8 years, he will be half of the age of his mother. How old is the mother at present ?

25. 48 4 36 32 6 A person’s present age is two-­fifth of the age of his mother. After 8 years, he will be half of the age of his mother. How old is the mother at present ?

26. 14:11 22:7 11:7 4:1 7 The perimeter of a circle is equal to the perimeter of a square. Then, the ratio of their areas respectively, is

27. 14:11 22:7 11:7 4:1 7 The perimeter of a circle is equal to the perimeter of a square. Then, the ratio of their areas respectively, is

28. 50 years 45 years 25 years 30 years 8 15 years ago, Kanika's father was five times as old as Kanika. After 15 years, her father will be thrice as old as her. The present age of Kanika is

29. 50 years 45 years 25 years 30 years 8 15 years ago, Kanika's father was five times as old as Kanika. After 15 years, her father will be thrice as old as her. The present age of Kanika is

30. Audience Question Count the number of squares in the figure.

31. AUDIENCE QUESTION 30

32. Round 3 Rules- Two question per team. Every team will be given 60 seconds to answer. Correct answer will be given 10 points. Wrong answer will be given -5 points. No pass questions allowed.

33. 1.

34. Answer 3

35. 2. Find the missing number

36. Answer 36

37. 3. Find the missing number

38. Answer 1

39. 4. In a garden, 40% of the flowers are roses, 30% are lilies, and the rest are daisies. If there are 150 daisies, how many flowers are there in total?

40. Answer 500 flowers

41. 5. A can do a piece of work in 10 days , and B can do the same work in 20 days . With the help of C , they finished the work in 4 days . C can do the work in how many days, working alone ?

42. Answer 10 Days

43. 6. A and B can do a piece of work in 5 days, B and C can do it in 7 days. A and C can do it in 4 days. Who among these will take the least time if put to do it alone ?

44. Answer A

45. 7. A man wants to reach a window which is 40ft. above the ground. The distance from the foot of the ladder to the wall is 9 feet. How long should the ladder be?.

46. Answer 41 feet

47. 8. A train is one mile long. It travels at the rate of one mile a minute through a tunnel which is also one mile long. Can you say how long it will take for the train to pass completely through the tunnel?.

48. Answer 2 minute

49. Round 4 Rules- One question per team. Every team will be given 60 seconds to answer. Correct answer will be given 10 points. Wrong answer will be given -5 points. No pass questions allowed.

50. 1. An aeroplane files twice is fast than a train which covers 60 miles in 80 minutes. What distance will the aeroplane cover in 20 minutes?

51. Answer 30 miles

52. 2. There is a number which is very peculiar. This number is three times the sum of its digits. Can you find the number?.

53. Answer 27

54. 2. There is a number which is very peculiar. This number is three times the sum of its digits. Can you find the number?.

55. Answer 27

56. 3. A rational number is such that when you multiply it by 5/2 and add 2/3 to the product, you get -7/12. What is the number?

57. Answer -1/2

58. 4. Find the measure of an interior angle of a regular polygon of 9 sides.

59. Answer 140

60. Round 5 Rules- Seven question per team. Every team will be given 100 seconds to answer as many as possible. All questions will be displayed at once. You many answer in any random order. Correct answer will be given 10 points. No negative marking.

61. A hollow pipe is 21cm long and its external diameter is 8cm. If the thickness of the pipe is 1cm, then find the volume of the pipe How many lead balls, each of radius 2cm can be made from a solid sphere of radius 16cm? A coin is tossed successively three times. Find the probability of getting exactly one head or two heads. If 2×3=812, 4×5=1620 then 6×7=? If Monday is to February, then Friday is to ? What is the missing number in the series: 2, 5, 10, 17, ?, 37 In a marathon race, John finishes 20 seconds ahead of Jack. If John's average speed is 15 km/h and Jack's average speed is 12 km/h, what is the length of the race?

62. 462 cu cm 512 ¾ 2428 June 26 4km

63. If the total surface area of a solid hemisphere is 462 sq.m , find its curved surface area. If the capacity of a cylindrical tank is 1848 cum and its base diameter is 14m,then find the depth of the tank. A bag contains 6 red balls and some white balls. If the probability of drawing a white ball is double that of a red ball. find the number of white balls in the bag. 3 3x-2 = 9 2x-2 find x. Find the sum of first 20 odd natural numbers. If 3 workers can complete a project in 10 days, how many workers are needed to complete the project in 5 days? The sum of the interior angles of a polygon is 1620 degrees. How many sides does the polygon have?

64. 308 sq cm 12 m 12 2 400 6 workers 10 sides

65. If the volumes of two cones are in the ratio 1:4 and their diameters are in the ratio 4:5, find the ratio of their heights. The radii of the bases of a cylinder and a cone are in the ratio 3:4 and their heights are in the ratio 2:3, find the ratio of their volumes. A card is drawn from a well shuffled deck of 52 cards. Find the probability that the card drawn will be neither a king nor a queen 2x-3y=5 and xy =4 Find 4 +9 . 1/3 : 1/4 ::20x : ? If a number is increased by 15% and then decreased by 10%, what is the net percentage change? The sum of two consecutive odd numbers is 104. What are the two numbers?  

66. 25:64 9:8 11/13 73 15x 4.5% increase 51 and 53

67. If each side of a cube is decreased by 25%, then find the ratio of volumes of original cube and the resulting new cube. Garvit was making a mathematical model, in which he placed 4 cubes each of edge 20cm one above the other. Find the surface area of resulting cuboid. A card is drawn from a well shuffled deck of 52 cards. Find the probability that the card drawn will be either a red card or a black face card 48, 45, 40, 33, 24 ......, ...... Point ‘A’ is located 8 km South of B and C is located 6 km West of A. what is the distance between C and B? A number, when divided by 5, leaves a remainder of 3. When the same number is divided by 7, it leaves a remainder of 4. What is the smallest possible value of the number? If March is to August, then C is to

68. 64:27 7200 sq cm 8/13 13,10 10km 18 H

69. TIE BREAKER A container contains a mixture of milk and water in the ratio of 5:3. If 15 liters of the mixture is replaced with pure milk, and then 10 liters of the new mixture is replaced with pure water, the final mixture has a ratio of milk to water as 4:3. Let the initial quantity of the mixture in the container is a/b. What is value of a & b

70. a = 40 and b =3

71. Thank You