Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 288 · 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 5 green, 5 white and 2 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/6 (b) 1/5 (c) 1/3 (d) 5/6
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 7/36 (b) 6/11 (c) 1/6 (d) 1/11
3. 3.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 7/8 (c) 1/7 (d) 1/8
4. 4.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 1/3 (c) 1/4 (d) 2/3
5. 5.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
6. 6.A bag has 2 yellow, 4 white and 5 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 7/11 (b) 1/3 (c) 4/11 (d) 8/11
7. 7.A bag has 7 white, 9 green and 7 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 9/23 (b) 1/3 (c) 15/23 (d) 14/23
8. 8.A bag has 2 white, 9 blue and 6 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 6/11 (c) 6/17 (d) 11/17
9. 9.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
10. 10.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
11. 11.A bag has 6 green, 3 yellow and 2 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 5/11 (c) 5/6 (d) 6/11
12. 12.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 3/4 (c) 1/4 (d) 1/2
13. 13.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 2/3 (b) 1/4 (c) 1/3 (d) 5/6
14. 14.A bag has 2 yellow, 7 white and 9 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 8/9 (b) 1/9 (c) 1/8 (d) 1/3
15. 15.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/6 (b) 1/5 (c) 1/3 (d) 5/6
16. 16.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
17. 17.A bag has 6 green, 3 red and 4 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 4/13 (b) 10/13 (c) 9/13 (d) 1/3
18. 18.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 1/4 (c) 3/4 (d) 1/3
19. 19.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 2/3 (b) 1/4 (c) 1/3 (d) 1/2
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 1/6 (c) 1/11 (d) 5/36
21. 21.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/5 (b) 1/6 (c) 5/6 (d) 1/3
22. 22.A bag has 6 red, 5 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 11/14 (b) 3/11 (c) 3/14 (d) 1/3
23. 23.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/18 (b) 1/12 (c) 1/11 (d) 1/36
24. 24.Three coins are tossed together. What is the probability of getting exactly one head? (a) 5/8 (b) 3/8 (c) 3/5 (d) 1/4
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 3/11 (b) 1/12 (c) 1/9 (d) 1/11
26. 26.A bag has 8 white, 5 green and 6 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 12/19 (c) 8/19 (d) 11/19
27. 27.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/8 (b) 3/4 (c) 1/8 (d) 1/4
28. 28.A bag has 9 green, 4 blue and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 2/3 (b) 1/3 (c) 8/21 (d) 13/21
29. 29.A bag has 3 white, 5 red and 9 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 15/17 (b) 1/3 (c) 14/17 (d) 3/17
30. 30.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/11 (b) 2/11 (c) 1/18 (d) 1/12
31. 31.A bag has 8 yellow, 4 white and 6 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/18 (b) 2/3 (c) 13/18 (d) 1/3
32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/9 (b) 3/11 (c) 1/12 (d) 1/11
33. 33.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/36 (b) 1/12 (c) 1/18 (d) 1/11
34. 34.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/11 (b) 5/36 (c) 1/11 (d) 1/6
35. 35.A bag has 3 blue, 7 red and 6 white 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
36. 36.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
37. 37.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/18 (b) 1/12 (c) 2/11 (d) 1/11
38. 38.A bag has 6 yellow, 3 red and 6 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 2/5 (b) 1/3 (c) 2/3 (d) 3/5
39. 39.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/3 (b) 5/6 (c) 1/4 (d) 2/3
40. 40.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/6 (b) 1/2 (c) 2/3 (d) 1/3

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