Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 125 · 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 fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
2. 2.A bag has 7 white, 5 yellow and 3 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 13/15 (b) 1/5 (c) 4/5 (d) 1/3
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 3/11 (b) 1/9 (c) 1/12 (d) 1/11
4. 4.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/4 (b) 1/3 (c) 2/3 (d) 5/6
5. 5.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/2 (c) 3/4 (d) 1/3
6. 6.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
7. 7.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/8 (b) 3/4 (c) 1/4 (d) 3/8
8. 8.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
9. 9.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
10. 10.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/7 (b) 7/8 (c) 1/4 (d) 1/8
11. 11.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 2/3 (c) 1/3 (d) 1/4
12. 12.A bag has 7 green, 9 white and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 5/21 (b) 16/21 (c) 17/21 (d) 1/3
13. 13.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
14. 14.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
15. 15.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 1/3 (c) 1/2 (d) 2/3
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/12 (b) 1/11 (c) 2/11 (d) 1/18
17. 17.A bag has 5 green, 9 yellow and 4 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/9 (b) 2/7 (c) 7/9 (d) 1/3
18. 18.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/5 (c) 3/8 (d) 5/8
19. 19.A bag has 9 green, 5 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) 15/22 (c) 7/11 (d) 1/3
20. 20.A bag has 2 red, 6 yellow and 8 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/2 (b) 1/3 (c) 1/16 (d) 9/16
21. 21.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 1/4 (c) 3/8 (d) 7/8
22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/9 (b) 5/36 (c) 4/11 (d) 1/11
23. 23.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/11 (b) 5/36 (c) 1/9 (d) 4/11
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/12 (c) 1/36 (d) 1/18
25. 25.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/2 (b) 1/4 (c) 1/3 (d) 2/3
26. 26.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
27. 27.A bag has 3 blue, 2 white and 2 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/5 (b) 5/7 (c) 2/7 (d) 1/3
28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/36 (b) 1/11 (c) 5/11 (d) 1/6
29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/9 (c) 1/12 (d) 1/11
30. 30.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
31. 31.A bag has 7 blue, 9 white and 4 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 1/4 (c) 1/5 (d) 4/5
32. 32.A bag has 6 white, 7 blue and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/21 (b) 2/3 (c) 5/7 (d) 1/3
33. 33.A bag has 2 blue, 3 white and 5 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 9/10 (b) 1/5 (c) 4/5 (d) 1/3
34. 34.A bag has 4 red, 2 white and 5 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/11 (b) 5/6 (c) 6/11 (d) 1/3
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/36 (c) 1/11 (d) 1/12
36. 36.A bag has 9 red, 7 green and 7 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 16/23 (b) 7/23 (c) 17/23 (d) 1/3
37. 37.A bag has 4 green, 2 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 4/7 (b) 3/7 (c) 9/14 (d) 1/3
38. 38.A bag has 7 white, 4 blue and 4 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 7/8 (c) 8/15 (d) 7/15
39. 39.A bag has 8 white, 4 green and 6 blue balls. One ball is taken out without looking. What is the probability that it is not white? (a) 5/9 (b) 1/3 (c) 11/18 (d) 4/9
40. 40.A bag has 6 green, 5 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 9/14 (b) 1/3 (c) 4/7 (d) 3/7

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