Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 161 · 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 white, 8 red and 2 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/8 (b) 1/3 (c) 3/5 (d) 5/8
2. 2.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/8 (c) 3/8 (d) 7/8
3. 3.A bag has 6 white, 3 yellow and 2 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 9/11 (b) 2/11 (c) 2/9 (d) 1/3
4. 4.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/4 (b) 1/4 (c) 1/8 (d) 3/8
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 6/11 (c) 1/11 (d) 7/36
6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 4/11 (b) 5/36 (c) 1/11 (d) 1/9
7. 7.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/3 (b) 1/5 (c) 1/6 (d) 5/6
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) 1/3 (d) 1/2
9. 9.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 1/3 (c) 1/4 (d) 5/6
10. 10.A bag has 4 green, 7 red and 3 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 4/7 (b) 1/3 (c) 1/2 (d) 1/14
11. 11.A bag has 4 blue, 6 red and 3 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/10 (b) 10/13 (c) 1/3 (d) 3/13
12. 12.A bag has 8 red, 7 green and 6 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 8/13 (b) 1/3 (c) 8/21 (d) 13/21
13. 13.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
14. 14.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/6
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/11 (b) 1/12 (c) 1/9 (d) 3/11
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/11 (b) 3/11 (c) 1/9 (d) 1/12
17. 17.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
18. 18.A bag has 9 green, 3 blue and 6 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 1/18 (c) 5/9 (d) 1/2
19. 19.A bag has 2 red, 5 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 7/10 (b) 3/10 (c) 4/5 (d) 1/3
20. 20.A bag has 3 white, 2 yellow and 2 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/4 (b) 1/3 (c) 3/7 (d) 4/7
21. 21.Three coins are tossed together. What is the probability of getting exactly one head? (a) 5/8 (b) 3/5 (c) 3/8 (d) 1/4
22. 22.A bag has 5 green, 4 blue and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 11/14 (b) 1/3 (c) 2/7 (d) 5/7
23. 23.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
24. 24.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) 2/3 (d) 1/2
25. 25.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 1/2 (c) 2/3 (d) 1/3
26. 26.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
27. 27.A bag has 6 green, 6 yellow and 7 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 12/19 (b) 7/19 (c) 7/12 (d) 1/3
28. 28.A bag has 6 white, 4 blue and 3 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 6/13 (c) 7/13 (d) 8/13
29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 2/11 (b) 1/18 (c) 1/12 (d) 1/11
30. 30.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/3 (b) 1/2 (c) 1/4 (d) 3/4
31. 31.A bag has 7 blue, 3 yellow and 4 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/14 (b) 11/14 (c) 1/3 (d) 3/11
32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/18 (c) 1/12 (d) 1/36
33. 33.A bag has 3 green, 7 yellow and 6 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 13/16 (b) 3/16 (c) 1/3 (d) 3/13
34. 34.A bag has 2 red, 3 green and 2 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 2/5 (b) 5/7 (c) 1/3 (d) 2/7
35. 35.A bag has 9 yellow, 2 white and 7 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/9 (b) 1/8 (c) 8/9 (d) 1/3
36. 36.A bag has 9 green, 6 yellow and 7 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 13/22 (b) 1/3 (c) 9/22 (d) 9/13
37. 37.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/18 (c) 1/36 (d) 1/12
38. 38.A bag has 6 green, 6 yellow and 5 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 11/17 (b) 12/17 (c) 6/17 (d) 1/3
39. 39.A bag has 6 red, 7 yellow and 9 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 3/11 (c) 17/22 (d) 8/11
40. 40.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 2/3 (c) 1/4 (d) 1/3

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