Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 139 · 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 6 green, 7 yellow and 4 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 6/17 (b) 11/17 (c) 1/3 (d) 6/11
2. 2.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
3. 3.A bag has 9 green, 4 white and 9 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 2/11 (b) 1/3 (c) 19/22 (d) 9/11
4. 4.Three coins are tossed together. What is the probability of getting at least one head? (a) 3/8 (b) 1/8 (c) 7/8 (d) 1/4
5. 5.A bag has 5 white, 2 green and 2 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/9 (b) 1/3 (c) 7/9 (d) 2/7
6. 6.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
7. 7.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
8. 8.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 1/4 (c) 5/8 (d) 3/8
9. 9.A bag has 7 green, 7 blue and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 13/19 (b) 7/19 (c) 12/19 (d) 1/3
10. 10.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/12 (b) 1/36 (c) 1/18 (d) 1/11
11. 11.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/8 (b) 3/8 (c) 3/4 (d) 1/4
12. 12.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/4 (b) 2/3 (c) 5/6 (d) 1/3
13. 13.A bag has 5 red, 8 white and 6 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 13/19 (c) 6/19 (d) 6/13
14. 14.A bag has 7 green, 3 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 3/13 (c) 10/13 (d) 11/13
15. 15.A bag has 3 blue, 8 white and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 12/19 (b) 8/19 (c) 11/19 (d) 1/3
16. 16.A bag has 5 green, 6 yellow and 7 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/18 (b) 5/13 (c) 1/3 (d) 13/18
17. 17.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 3/4 (b) 1/2 (c) 1/4 (d) 1/3
18. 18.A bag has 7 green, 2 red and 4 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 6/13 (b) 7/13 (c) 6/7 (d) 1/3
19. 19.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
20. 20.A bag has 5 white, 8 green and 2 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/15 (b) 1/3 (c) 8/15 (d) 3/5
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/36 (c) 1/18 (d) 1/12
22. 22.A bag has 3 white, 2 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 3/13 (c) 10/13 (d) 11/13
23. 23.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 1/11 (c) 2/11 (d) 1/18
24. 24.A bag has 6 blue, 8 red and 2 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 3/8 (b) 1/3 (c) 11/16 (d) 5/8
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 3/11 (c) 1/12 (d) 1/11
26. 26.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
27. 27.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/5 (b) 1/6 (c) 1/3 (d) 5/6
28. 28.A bag has 5 white, 3 yellow and 2 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 1/10 (c) 3/5 (d) 1/2
29. 29.A bag has 8 red, 2 yellow and 5 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 11/15 (b) 1/3 (c) 2/3 (d) 1/15
30. 30.A bag has 4 blue, 7 red and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 3/5 (c) 8/15 (d) 7/15
31. 31.A bag has 7 yellow, 9 red and 2 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/9 (b) 1/18 (c) 1/2 (d) 1/3
32. 32.A bag has 8 red, 3 blue and 5 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 9/16 (b) 1/3 (c) 1/2 (d) 1/16
33. 33.A bag has 4 green, 8 white and 7 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 11/19 (b) 1/3 (c) 8/19 (d) 8/11
34. 34.A bag has 5 blue, 7 yellow and 6 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 7/18 (b) 2/3 (c) 1/3 (d) 11/18
35. 35.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
36. 36.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 4/11 (b) 1/11 (c) 1/9 (d) 5/36
37. 37.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
38. 38.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 2/3 (c) 1/2 (d) 1/3
39. 39.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/8 (b) 1/7 (c) 7/8 (d) 1/4
40. 40.A bag has 3 red, 7 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 7/13 (b) 6/13 (c) 6/7 (d) 1/3

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