Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 391 · 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 even number? (a) 1/3 (b) 2/3 (c) 1/2 (d) 1/6
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/6 (b) 5/11 (c) 1/11 (d) 5/36
3. 3.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
4. 4.A bag has 4 green, 9 yellow and 5 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 7/9 (c) 5/6 (d) 2/9
5. 5.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 2/3 (c) 1/4 (d) 5/6
6. 6.A bag has 4 blue, 9 red and 6 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 6/13 (b) 6/19 (c) 13/19 (d) 1/3
7. 7.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
8. 8.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
9. 9.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/5 (c) 3/8 (d) 5/8
10. 10.A bag has 2 yellow, 5 white and 2 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 2/9 (b) 1/3 (c) 2/7 (d) 7/9
11. 11.Two coins are tossed together. What is the probability of getting at least one head? (a) 3/4 (b) 1/4 (c) 1/2 (d) 1/3
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/11 (b) 2/11 (c) 1/12 (d) 1/18
13. 13.A bag has 3 green, 3 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 3/14 (c) 6/7 (d) 11/14
14. 14.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 3/4 (b) 1/3 (c) 1/4 (d) 1/2
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/18 (b) 1/11 (c) 1/12 (d) 1/36
16. 16.A bag has 4 green, 2 white and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 2/3 (b) 1/3 (c) 4/9 (d) 5/9
17. 17.A bag has 6 blue, 2 red and 5 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 2/13 (b) 11/13 (c) 1/3 (d) 12/13
18. 18.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
19. 19.A bag has 6 blue, 8 white and 8 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 4/7 (b) 7/11 (c) 4/11 (d) 1/3
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 1/18 (c) 2/11 (d) 1/12
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/11 (b) 3/11 (c) 1/12 (d) 1/9
22. 22.A bag has 9 yellow, 7 white and 4 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 4/5 (b) 1/3 (c) 1/4 (d) 1/5
23. 23.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/6 (b) 1/2 (c) 2/3 (d) 1/3
24. 24.A bag has 2 yellow, 6 white and 5 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 7/13 (c) 8/13 (d) 6/13
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/12 (b) 1/18 (c) 1/36 (d) 1/11
26. 26.A bag has 6 red, 7 yellow and 9 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 8/11 (b) 1/3 (c) 3/11 (d) 17/22
27. 27.A bag has 8 yellow, 5 red and 6 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 8/11 (b) 11/19 (c) 8/19 (d) 1/3
28. 28.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
29. 29.A bag has 9 green, 9 blue and 3 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 6/7 (b) 1/7 (c) 19/21 (d) 1/3
30. 30.A bag has 3 blue, 3 white and 6 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/2 (b) 7/12 (c) 1/12 (d) 1/3
31. 31.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/8 (b) 1/4 (c) 7/8 (d) 1/7
32. 32.A bag has 8 red, 8 green and 7 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 7/23 (b) 17/23 (c) 16/23 (d) 1/3
33. 33.A bag has 7 yellow, 6 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 17/22 (b) 8/11 (c) 1/3 (d) 3/11
34. 34.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
35. 35.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 3/8 (c) 1/8 (d) 7/8
36. 36.A bag has 2 red, 6 white and 6 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 6/7 (b) 1/6 (c) 1/7 (d) 1/3
37. 37.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
38. 38.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 1/8 (c) 3/8 (d) 3/4
39. 39.A bag has 9 yellow, 7 red and 8 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 17/24 (c) 7/17 (d) 7/24
40. 40.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 2/3 (c) 1/4 (d) 1/3

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