Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 74 · 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 fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
3. 3.A bag has 3 white, 8 red and 9 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 11/20 (c) 9/20 (d) 9/11
4. 4.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/2 (b) 1/6 (c) 1/3 (d) 2/3
5. 5.A bag has 5 green, 3 white and 8 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 13/16 (b) 3/16 (c) 1/3 (d) 3/13
6. 6.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
7. 7.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 1/4 (c) 5/8 (d) 3/5
8. 8.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/6 (b) 1/5 (c) 5/6 (d) 1/3
9. 9.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/36 (c) 1/12 (d) 1/11
10. 10.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
11. 11.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 1/4 (c) 5/6 (d) 2/3
12. 12.A bag has 8 red, 7 green and 6 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 5/7 (c) 2/7 (d) 2/5
13. 13.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 1/4 (c) 2/3 (d) 1/2
14. 14.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) 1/2 (d) 2/3
15. 15.A bag has 2 blue, 6 white and 8 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/5 (b) 3/8 (c) 5/8 (d) 1/3
16. 16.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/9 (b) 5/36 (c) 4/11 (d) 1/11
18. 18.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/36 (b) 1/6 (c) 1/11 (d) 5/11
19. 19.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
20. 20.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
21. 21.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
22. 22.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
23. 23.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 3/4 (c) 1/3 (d) 1/4
24. 24.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
25. 25.A bag has 3 green, 4 yellow and 9 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 7/16 (b) 9/16 (c) 5/8 (d) 1/3
26. 26.A bag has 9 yellow, 5 green and 4 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/9 (b) 2/7 (c) 1/3 (d) 7/9
27. 27.A bag has 5 green, 3 white and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 5/12 (c) 7/12 (d) 2/3
28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 7/36 (c) 1/11 (d) 6/11
29. 29.A bag has 6 white, 6 red and 5 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 13/17 (c) 5/17 (d) 12/17
30. 30.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
31. 31.A bag has 6 blue, 6 yellow and 5 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 12/17 (c) 5/17 (d) 13/17
32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 5/36 (b) 4/11 (c) 1/9 (d) 1/11
33. 33.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/9 (b) 1/11 (c) 1/12 (d) 3/11
34. 34.A bag has 6 red, 6 green and 4 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 11/16 (c) 3/8 (d) 5/8
35. 35.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 7/8 (c) 3/8 (d) 1/8
36. 36.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/4 (b) 5/6 (c) 1/3 (d) 2/3
37. 37.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/18 (b) 1/36 (c) 1/11 (d) 1/12
38. 38.A bag has 6 white, 8 green and 4 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 13/18 (c) 2/3 (d) 1/18
39. 39.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
40. 40.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/3 (b) 1/4 (c) 5/6 (d) 2/3

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