Probability Worksheet for Class 8 Maths Olympiad

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

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