Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 640 · 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 4? (a) 1/9 (b) 1/12 (c) 1/11 (d) 3/11
2. 2.A bag has 4 green, 9 yellow and 8 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 6/7 (b) 17/21 (c) 1/3 (d) 4/21
3. 3.A bag has 4 red, 6 white and 6 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/8 (b) 3/5 (c) 1/3 (d) 3/8
4. 4.A bag has 8 red, 6 white and 5 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 8/11 (b) 11/19 (c) 8/19 (d) 1/3
5. 5.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 1/4 (c) 3/5 (d) 5/8
6. 6.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/8 (b) 1/4 (c) 3/4 (d) 1/8
7. 7.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
8. 8.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
9. 9.A bag has 7 red, 7 white and 8 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 15/22 (b) 7/22 (c) 7/15 (d) 1/3
10. 10.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/5 (b) 1/3 (c) 1/6 (d) 5/6
11. 11.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/4
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/12 (b) 1/36 (c) 1/11 (d) 1/18
13. 13.A bag has 7 green, 7 white and 8 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 4/11 (b) 7/11 (c) 15/22 (d) 1/3
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 2/11 (c) 1/18 (d) 1/12
15. 15.A bag has 9 green, 8 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 17/26 (b) 1/3 (c) 9/13 (d) 9/26
16. 16.Two coins are tossed together. What is the probability of getting exactly one head? (a) 2/3 (b) 1/4 (c) 1/2 (d) 1/3
17. 17.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
18. 18.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
19. 19.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
20. 20.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/7 (c) 1/8 (d) 7/8
21. 21.A bag has 6 red, 3 blue and 5 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/11 (b) 11/14 (c) 3/14 (d) 1/3
22. 22.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 2/3 (c) 5/6 (d) 1/4
23. 23.A bag has 5 green, 7 yellow and 6 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 13/18 (b) 1/3 (c) 5/18 (d) 7/9
24. 24.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
25. 25.A bag has 7 red, 3 blue and 9 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 3/19 (c) 17/19 (d) 16/19
26. 26.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/9 (b) 3/11 (c) 1/12 (d) 1/11
27. 27.A bag has 4 blue, 6 green and 5 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/5 (b) 1/3 (c) 1/2 (d) 2/3
28. 28.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 3/4 (c) 1/2 (d) 1/3
29. 29.A bag has 3 red, 5 blue and 9 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 8/17 (b) 1/3 (c) 9/17 (d) 10/17
30. 30.A bag has 4 green, 8 white and 9 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 8/21 (b) 8/13 (c) 13/21 (d) 1/3
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 1/11 (c) 1/9 (d) 4/11
32. 32.A bag has 5 yellow, 8 blue and 2 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/13 (b) 13/15 (c) 2/15 (d) 1/3
33. 33.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
34. 34.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 2/3 (b) 1/3 (c) 1/4 (d) 5/6
35. 35.A bag has 4 red, 2 blue and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 4/5 (b) 1/3 (c) 1/5 (d) 9/10
36. 36.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
37. 37.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 4/11 (b) 1/9 (c) 5/36 (d) 1/11
38. 38.A bag has 8 red, 6 blue and 7 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 8/21 (b) 2/3 (c) 1/3 (d) 1/2
39. 39.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/4 (b) 5/6 (c) 1/3 (d) 2/3
40. 40.A bag has 8 yellow, 8 white and 7 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 15/23 (c) 8/23 (d) 8/15

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