Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 931 · 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 bag has 7 blue, 7 white and 8 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 15/22 (b) 7/15 (c) 7/22 (d) 1/3
2. 2.A bag has 4 blue, 5 green and 2 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 10/11 (c) 2/11 (d) 9/11
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 5/36 (b) 1/9 (c) 1/11 (d) 4/11
4. 4.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/8 (c) 5/8 (d) 3/5
5. 5.A bag has 9 yellow, 2 red and 6 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 16/17 (b) 1/3 (c) 2/17 (d) 15/17
6. 6.A bag has 4 yellow, 6 white and 8 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/9 (b) 1/3 (c) 2/7 (d) 2/9
7. 7.A bag has 4 red, 2 yellow and 2 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 3/4 (b) 3/8 (c) 1/4 (d) 1/3
8. 8.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
9. 9.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/36 (b) 5/11 (c) 1/11 (d) 1/6
10. 10.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 2/11 (b) 1/18 (c) 1/12 (d) 1/11
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/9 (b) 1/11 (c) 5/36 (d) 4/11
13. 13.A bag has 4 green, 2 blue and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 4/11 (b) 7/11 (c) 1/3 (d) 8/11
14. 14.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/3 (c) 3/4 (d) 1/2
15. 15.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
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 7/36 (c) 6/11 (d) 1/11
17. 17.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
18. 18.A bag has 5 white, 2 blue and 9 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 5/16 (b) 11/16 (c) 1/3 (d) 5/11
19. 19.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
20. 20.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 1/4 (c) 2/3 (d) 1/3
21. 21.A bag has 9 green, 5 blue and 9 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 9/23 (c) 15/23 (d) 14/23
22. 22.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
23. 23.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 3/11 (b) 1/11 (c) 1/12 (d) 1/9
25. 25.A bag has 8 green, 4 blue and 4 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/4 (b) 5/16 (c) 3/4 (d) 1/3
26. 26.A bag has 2 green, 8 red and 3 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/13 (b) 9/13 (c) 1/3 (d) 8/13
27. 27.A bag has 6 yellow, 3 white and 8 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 8/17 (c) 9/17 (d) 10/17
28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/6 (b) 1/11 (c) 5/36 (d) 5/11
29. 29.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/4 (c) 1/7 (d) 1/8
30. 30.A bag has 8 red, 7 green and 2 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/17 (b) 2/15 (c) 1/3 (d) 15/17
31. 31.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 3/8 (c) 1/4 (d) 7/8
32. 32.A bag has 7 red, 2 white and 7 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 9/16 (b) 7/16 (c) 1/3 (d) 5/8
33. 33.A bag has 7 blue, 9 red and 8 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/3 (b) 1/3 (c) 3/8 (d) 1/2
34. 34.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 2/3 (b) 1/3 (c) 5/6 (d) 1/4
35. 35.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
36. 36.A bag has 9 white, 7 red and 7 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/16 (b) 16/23 (c) 7/23 (d) 1/3
37. 37.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 2/3 (b) 1/4 (c) 1/2 (d) 1/3
38. 38.A bag has 4 yellow, 3 white and 3 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 2/5 (b) 2/3 (c) 3/5 (d) 1/3
39. 39.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) 1/8 (d) 1/4
40. 40.A bag has 9 yellow, 6 white and 3 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/6 (b) 1/3 (c) 5/6 (d) 8/9

Free maths olympiad lessons, practice and worksheets at talentjr.in/maths-olympiad