Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 80 · 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 a multiple of 3? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
2. 2.A bag has 7 white, 3 red and 9 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/19 (b) 16/19 (c) 1/3 (d) 3/16
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 1/12 (c) 1/18 (d) 2/11
4. 4.A bag has 8 green, 3 white and 9 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 17/20 (b) 1/3 (c) 3/17 (d) 3/20
5. 5.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
6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/18 (c) 1/12 (d) 1/36
7. 7.A bag has 3 white, 6 red and 9 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/5 (b) 1/6 (c) 5/6 (d) 1/3
8. 8.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
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 greater than 4? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
11. 11.A bag has 3 blue, 2 green and 4 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 4/9 (b) 2/3 (c) 1/3 (d) 1/2
12. 12.A bag has 8 white, 3 blue and 6 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 11/17 (c) 6/17 (d) 12/17
13. 13.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/11 (b) 5/36 (c) 1/6 (d) 5/11
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/12 (c) 1/18 (d) 1/36
16. 16.A bag has 9 white, 6 red and 9 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 3/4 (c) 7/24 (d) 1/4
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 6/11 (b) 1/11 (c) 7/36 (d) 1/6
18. 18.A bag has 3 yellow, 8 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/5 (b) 1/3 (c) 2/3 (d) 3/5
19. 19.A bag has 8 white, 7 green and 9 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 17/24 (c) 3/4 (d) 7/24
20. 20.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 3/4 (c) 1/3 (d) 1/2
21. 21.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 7/8 (c) 3/8 (d) 1/4
22. 22.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/5 (b) 1/6 (c) 1/3 (d) 5/6
23. 23.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 1/11 (c) 4/11 (d) 1/9
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) 1/11 (d) 1/9
25. 25.A bag has 5 blue, 6 yellow and 8 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 13/19 (b) 1/3 (c) 6/19 (d) 6/13
26. 26.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/3 (b) 1/4 (c) 2/3 (d) 5/6
27. 27.A bag has 7 green, 5 red and 4 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 5/16 (b) 11/16 (c) 3/4 (d) 1/3
28. 28.A bag has 4 white, 2 blue and 2 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 1/8 (c) 5/8 (d) 1/2
29. 29.A bag has 8 red, 7 blue and 2 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 2/17 (b) 16/17 (c) 1/3 (d) 15/17
30. 30.A bag has 7 green, 3 yellow and 6 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 5/8 (b) 1/3 (c) 7/16 (d) 9/16
31. 31.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/3 (b) 1/4 (c) 5/6 (d) 2/3
32. 32.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 1/3 (c) 2/3 (d) 1/2
33. 33.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
34. 34.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 5/8 (c) 3/8 (d) 1/4
35. 35.A bag has 3 yellow, 5 green and 2 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 4/5 (b) 1/3 (c) 9/10 (d) 1/5
36. 36.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
37. 37.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 3/4 (b) 1/4 (c) 1/2 (d) 1/3
38. 38.A bag has 7 white, 8 green and 3 blue balls. One ball is taken out without looking. What is the probability that it is not white? (a) 11/18 (b) 7/18 (c) 1/3 (d) 2/3
39. 39.A bag has 5 green, 8 white and 5 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 13/18 (b) 1/3 (c) 5/18 (d) 7/9
40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 1/11 (c) 3/11 (d) 1/9

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