Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 317 · 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.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/12 (c) 1/36 (d) 1/11
2. 2.A bag has 4 yellow, 7 green and 8 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 4/15 (b) 15/19 (c) 1/3 (d) 4/19
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/9 (b) 4/11 (c) 5/36 (d) 1/11
4. 4.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
5. 5.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
6. 6.A bag has 8 white, 7 yellow and 3 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 7/18 (c) 11/18 (d) 2/3
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/11 (b) 3/11 (c) 1/9 (d) 1/12
8. 8.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/2 (b) 1/3 (c) 1/6 (d) 2/3
9. 9.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 1/4 (c) 1/3 (d) 5/6
10. 10.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
11. 11.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/8 (b) 3/4 (c) 1/4 (d) 1/8
12. 12.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/3 (b) 1/4 (c) 1/2 (d) 2/3
13. 13.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
14. 14.Three coins are tossed together. What is the probability of getting at least one head? (a) 7/8 (b) 1/8 (c) 1/4 (d) 3/8
15. 15.A bag has 8 green, 2 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/9 (b) 17/18 (c) 8/9 (d) 1/3
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/6 (b) 5/36 (c) 1/11 (d) 5/11
17. 17.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 3/4 (b) 1/3 (c) 1/2 (d) 1/4
18. 18.A bag has 5 white, 2 green and 9 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 7/9 (b) 1/3 (c) 7/16 (d) 9/16
19. 19.A bag has 2 yellow, 7 green and 9 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 11/18 (b) 7/11 (c) 1/3 (d) 7/18
20. 20.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/2 (b) 1/6 (c) 2/3 (d) 1/3
21. 21.A bag has 7 red, 4 white and 5 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/4 (b) 3/4 (c) 1/3 (d) 5/16
22. 22.Three coins are tossed together. What is the probability of getting exactly one head? (a) 5/8 (b) 1/4 (c) 3/8 (d) 3/5
23. 23.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/6 (b) 1/5 (c) 1/3 (d) 5/6
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 2/11 (c) 1/18 (d) 1/11
25. 25.A bag has 4 green, 6 yellow and 5 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/15 (b) 11/15 (c) 1/3 (d) 2/3
26. 26.A bag has 4 red, 4 green and 8 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/4 (b) 1/3 (c) 5/16 (d) 1/4
27. 27.A bag has 8 green, 5 blue and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 8/21 (b) 13/21 (c) 1/3 (d) 2/3
28. 28.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/2 (c) 3/4 (d) 1/3
29. 29.A bag has 9 green, 4 blue and 8 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 3/4 (c) 4/7 (d) 3/7
30. 30.A bag has 6 red, 7 white and 9 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/11 (b) 1/3 (c) 17/22 (d) 8/11
31. 31.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
32. 32.A bag has 7 white, 6 red and 4 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 6/17 (b) 11/17 (c) 12/17 (d) 1/3
33. 33.A bag has 3 green, 5 yellow and 7 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/5 (b) 13/15 (c) 1/3 (d) 4/5
34. 34.A bag has 7 red, 7 yellow and 5 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 12/19 (c) 7/12 (d) 7/19
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/36 (b) 1/11 (c) 1/12 (d) 1/18
36. 36.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/11 (c) 1/12 (d) 1/9
37. 37.A bag has 8 red, 6 green and 2 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 9/16 (c) 1/16 (d) 1/2
38. 38.A bag has 8 green, 5 red and 7 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 7/20 (b) 7/13 (c) 1/3 (d) 13/20
39. 39.A bag has 4 blue, 7 red and 4 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/5 (b) 8/15 (c) 7/15 (d) 1/3
40. 40.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2

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