Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 96 · 40 questions

How to solve it (Favourable over total): Probability = number of favourable outcomes ÷ total number of equally likely outcomes. List the outcomes: a dice has 6, two coins have 4 (HH, HT, TH, TT), three coins have 8, two dice have 36. Write the answer as a fraction in its lowest terms; a probability is never more than 1.

1. 1.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
2. 2.A bag has 3 yellow, 3 blue and 5 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/6 (b) 5/11 (c) 1/3 (d) 6/11
3. 3.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/2 (b) 1/4 (c) 1/3 (d) 3/4
4. 4.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
5. 5.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/9 (b) 5/36 (c) 1/11 (d) 4/11
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/36 (b) 1/11 (c) 1/12 (d) 1/18
8. 8.A bag has 2 blue, 2 yellow and 2 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 2/3 (c) 1/2 (d) 1/6
9. 9.A bag has 2 blue, 6 white and 3 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 8/11 (c) 9/11 (d) 3/11
10. 10.A bag has 9 red, 9 green and 4 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 13/22 (b) 1/3 (c) 9/22 (d) 9/13
11. 11.A bag has 7 red, 8 green and 7 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 15/22 (b) 1/3 (c) 7/22 (d) 8/11
12. 12.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
13. 13.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/11 (b) 1/12 (c) 1/18 (d) 2/11
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 5/36 (c) 1/6 (d) 1/11
16. 16.A bag has 3 red, 3 blue and 6 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 5/6 (b) 1/4 (c) 3/4 (d) 1/3
17. 17.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/4 (b) 1/3 (c) 5/6 (d) 2/3
18. 18.A bag has 3 white, 7 red and 9 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 10/19 (c) 9/19 (d) 9/10
19. 19.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 5/6 (b) 2/3 (c) 1/4 (d) 1/3
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/11 (b) 3/11 (c) 1/12 (d) 1/9
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/6 (b) 5/36 (c) 5/11 (d) 1/11
22. 22.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 1/4 (c) 3/8 (d) 5/8
23. 23.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/4 (b) 1/4 (c) 1/8 (d) 3/8
24. 24.A bag has 5 green, 9 red and 9 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 5/23 (c) 19/23 (d) 18/23
25. 25.A bag has 2 white, 7 red and 4 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 6/13 (b) 7/13 (c) 6/7 (d) 1/3
26. 26.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/7 (c) 7/8 (d) 1/8
27. 27.A bag has 9 yellow, 8 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 3/20 (c) 9/10 (d) 17/20
28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 7/36 (b) 1/11 (c) 6/11 (d) 1/6
29. 29.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/2 (c) 1/3 (d) 3/4
30. 30.A bag has 7 yellow, 7 red and 4 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/18 (b) 1/3 (c) 7/11 (d) 11/18
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/36 (b) 1/18 (c) 1/12 (d) 1/11
32. 32.A bag has 2 white, 2 blue and 6 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/5 (b) 1/3 (c) 9/10 (d) 4/5
33. 33.A bag has 7 green, 5 red and 4 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/16 (b) 1/3 (c) 1/4 (d) 3/4
34. 34.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/11 (b) 1/9 (c) 4/11 (d) 5/36
35. 35.A bag has 2 red, 5 blue and 8 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/3 (b) 2/5 (c) 1/3 (d) 1/2
36. 36.A bag has 8 blue, 4 red and 2 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 4/7 (c) 9/14 (d) 3/7
37. 37.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/6 (b) 5/6 (c) 1/5 (d) 1/3
38. 38.A bag has 6 red, 5 white and 9 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 7/10 (c) 3/10 (d) 3/7
39. 39.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
40. 40.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/4 (b) 1/3 (c) 2/3 (d) 5/6

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