Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 950 · 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.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/4 (b) 1/8 (c) 1/4 (d) 3/8
2. 2.A bag has 8 green, 8 white and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 8/19 (b) 12/19 (c) 11/19 (d) 1/3
3. 3.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 1/6 (c) 1/3 (d) 2/3
4. 4.A bag has 5 yellow, 2 white and 8 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 2/3 (b) 2/5 (c) 1/2 (d) 1/3
5. 5.A bag has 7 green, 8 yellow and 2 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 8/9 (b) 9/17 (c) 8/17 (d) 1/3
6. 6.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
7. 7.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/4 (c) 3/4 (d) 1/2
8. 8.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/7 (b) 7/8 (c) 1/4 (d) 1/8
9. 9.A bag has 6 red, 8 yellow and 4 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 13/18 (c) 1/18 (d) 2/3
10. 10.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/12 (b) 1/11 (c) 2/11 (d) 1/18
11. 11.A bag has 9 green, 8 white and 8 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 9/25 (b) 1/3 (c) 17/25 (d) 16/25
12. 12.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 2/3 (c) 1/3 (d) 1/2
13. 13.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/11 (b) 1/9 (c) 1/12 (d) 3/11
15. 15.A bag has 3 yellow, 2 green and 5 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/10 (b) 1/3 (c) 3/7 (d) 3/10
16. 16.A bag has 5 white, 3 blue and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 9/16 (b) 1/3 (c) 1/2 (d) 1/16
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/11 (b) 1/9 (c) 5/36 (d) 4/11
18. 18.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
19. 19.A bag has 9 white, 7 yellow and 7 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 7/23 (b) 17/23 (c) 1/3 (d) 16/23
20. 20.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/3 (b) 2/3 (c) 1/4 (d) 5/6
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/9 (b) 1/11 (c) 3/11 (d) 1/12
22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/6 (b) 1/11 (c) 5/36 (d) 5/11
23. 23.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 6/11 (c) 7/36 (d) 1/11
25. 25.A bag has 7 yellow, 9 green and 4 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/5 (b) 4/5 (c) 1/4 (d) 1/3
26. 26.A bag has 4 yellow, 9 green and 4 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 4/13 (b) 1/3 (c) 13/17 (d) 4/17
27. 27.A bag has 7 red, 8 white and 7 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 4/11 (c) 15/22 (d) 7/11
28. 28.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
29. 29.A bag has 2 red, 2 green and 8 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/12 (b) 3/4 (c) 1/3 (d) 2/3
30. 30.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 1/4 (c) 1/3 (d) 2/3
31. 31.A bag has 3 blue, 5 green and 5 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/10 (b) 3/13 (c) 10/13 (d) 1/3
32. 32.A bag has 6 red, 5 blue and 3 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/4 (b) 1/3 (c) 3/7 (d) 4/7
33. 33.A bag has 7 yellow, 3 white and 4 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 11/14 (b) 5/7 (c) 1/3 (d) 2/7
34. 34.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/12 (b) 1/36 (c) 1/18 (d) 1/11
35. 35.A bag has 4 green, 9 red and 2 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 2/13 (c) 13/15 (d) 2/15
36. 36.Two coins are tossed together. What is the probability of getting at least one head? (a) 3/4 (b) 1/2 (c) 1/4 (d) 1/3
37. 37.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/18 (b) 1/11 (c) 2/11 (d) 1/12
38. 38.A bag has 6 yellow, 4 green and 5 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 2/5 (b) 2/3 (c) 1/3 (d) 3/5
39. 39.Three coins are tossed together. What is the probability of getting at least one head? (a) 3/8 (b) 7/8 (c) 1/8 (d) 1/4
40. 40.A bag has 9 white, 3 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 3/7 (b) 1/3 (c) 4/7 (d) 13/21

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