Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 124 · 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 2 red, 4 green and 8 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 6/7 (b) 1/6 (c) 1/3 (d) 1/7
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 3/11 (b) 1/9 (c) 1/11 (d) 1/12
3. 3.A bag has 5 blue, 8 white and 3 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/11 (b) 1/3 (c) 11/16 (d) 5/16
4. 4.A bag has 6 red, 5 yellow and 3 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 3/4 (c) 3/7 (d) 4/7
5. 5.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 5/8 (c) 1/4 (d) 3/5
6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/18 (c) 1/36 (d) 1/12
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/11 (b) 6/11 (c) 1/6 (d) 7/36
8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/36 (b) 1/11 (c) 5/11 (d) 1/6
9. 9.A bag has 8 red, 8 white and 7 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 17/23 (c) 16/23 (d) 7/23
10. 10.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/3 (b) 1/5 (c) 5/6 (d) 1/6
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/18 (b) 1/11 (c) 1/12 (d) 2/11
12. 12.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/7 (c) 1/8 (d) 1/4
13. 13.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
14. 14.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) 1/4 (d) 3/4
15. 15.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
16. 16.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/4
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 4/11 (b) 5/36 (c) 1/9 (d) 1/11
18. 18.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 3/4 (c) 1/4 (d) 1/3
19. 19.A bag has 6 red, 7 green and 7 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/13 (b) 1/3 (c) 13/20 (d) 7/20
20. 20.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
21. 21.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/2 (c) 1/3 (d) 3/4
22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/11 (c) 1/36 (d) 1/12
23. 23.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
24. 24.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
25. 25.A bag has 5 green, 4 red and 5 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/5 (b) 2/7 (c) 1/3 (d) 5/7
26. 26.A bag has 2 green, 2 white and 3 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/4 (b) 1/3 (c) 4/7 (d) 3/7
27. 27.A bag has 7 green, 9 red and 8 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 1/2 (c) 3/8 (d) 2/3
28. 28.A bag has 8 red, 5 white and 3 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/13 (b) 13/16 (c) 3/16 (d) 1/3
29. 29.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
30. 30.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/11 (b) 1/18 (c) 2/11 (d) 1/12
31. 31.A bag has 7 white, 2 green and 4 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 4/9 (b) 9/13 (c) 4/13 (d) 1/3
32. 32.A bag has 7 red, 2 white and 3 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 5/6 (b) 1/4 (c) 1/3 (d) 3/4
33. 33.A bag has 5 white, 4 green and 2 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 4/7 (b) 7/11 (c) 1/3 (d) 4/11
34. 34.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
35. 35.A bag has 3 blue, 9 red and 4 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 13/16 (b) 1/3 (c) 7/8 (d) 3/16
36. 36.A bag has 2 yellow, 5 blue and 7 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 6/7 (b) 1/6 (c) 1/7 (d) 1/3
37. 37.A bag has 9 green, 6 yellow and 9 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/8 (b) 3/8 (c) 1/3 (d) 3/5
38. 38.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
39. 39.A bag has 4 green, 4 red and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 8/11 (b) 3/11 (c) 1/3 (d) 9/11
40. 40.A bag has 5 blue, 3 red and 6 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 5/7 (b) 5/14 (c) 9/14 (d) 1/3

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