Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 418 · 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 blue, 7 red and 6 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/3 (b) 1/2 (c) 7/18 (d) 1/3
2. 2.A bag has 6 white, 2 blue and 3 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 5/6 (b) 5/11 (c) 1/3 (d) 6/11
3. 3.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
4. 4.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/11 (b) 1/6 (c) 5/11 (d) 5/36
6. 6.A bag has 8 white, 9 yellow and 2 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 10/19 (c) 9/19 (d) 9/10
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) 1/4 (c) 3/4 (d) 3/8
8. 8.A bag has 7 red, 8 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) 12/19 (c) 7/19 (d) 13/19
9. 9.A bag has 5 white, 3 green and 7 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 4/5 (b) 1/3 (c) 13/15 (d) 1/5
10. 10.A bag has 2 white, 9 green and 5 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/8 (b) 9/16 (c) 7/16 (d) 1/3
11. 11.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
12. 12.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
13. 13.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 3/11 (b) 1/12 (c) 1/11 (d) 1/9
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/11 (b) 4/11 (c) 5/36 (d) 1/9
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 6/11 (b) 7/36 (c) 1/6 (d) 1/11
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/36 (b) 1/18 (c) 1/11 (d) 1/12
17. 17.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 2/3 (c) 1/4 (d) 5/6
18. 18.Two coins are tossed together. What is the probability of getting at least one head? (a) 3/4 (b) 1/2 (c) 1/3 (d) 1/4
19. 19.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/3 (b) 2/3 (c) 1/4 (d) 1/2
20. 20.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
21. 21.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/4 (b) 2/3 (c) 1/3 (d) 5/6
22. 22.A bag has 6 blue, 6 yellow and 3 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/5 (b) 2/3 (c) 1/3 (d) 2/5
23. 23.Three coins are tossed together. What is the probability of getting at least one head? (a) 7/8 (b) 3/8 (c) 1/4 (d) 1/8
24. 24.A bag has 9 red, 9 green and 4 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 9/11 (b) 2/11 (c) 1/3 (d) 2/9
25. 25.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
26. 26.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/8 (b) 7/8 (c) 1/7 (d) 1/4
27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 2/11 (b) 1/18 (c) 1/12 (d) 1/11
28. 28.A bag has 2 white, 3 yellow and 2 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/5 (b) 1/3 (c) 5/7 (d) 2/7
29. 29.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
30. 30.Three coins are tossed together. What is the probability of getting exactly one head? (a) 5/8 (b) 3/8 (c) 1/4 (d) 3/5
31. 31.A bag has 3 red, 8 blue and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 5/16 (b) 11/16 (c) 1/3 (d) 3/4
32. 32.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 2/3 (c) 1/4 (d) 1/2
33. 33.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/6 (b) 5/36 (c) 1/11 (d) 5/11
34. 34.A bag has 6 blue, 4 yellow and 6 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/4 (b) 3/4 (c) 1/3 (d) 5/16
35. 35.A bag has 2 blue, 9 green and 5 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 5/8 (c) 7/16 (d) 9/16
36. 36.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
37. 37.A bag has 8 yellow, 3 blue and 9 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 9/20 (c) 3/5 (d) 11/20
38. 38.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/11 (b) 3/11 (c) 1/12 (d) 1/9
39. 39.A bag has 6 red, 9 green and 3 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/18 (b) 13/18 (c) 1/3 (d) 2/3
40. 40.A bag has 2 white, 7 green and 8 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/17 (b) 15/17 (c) 1/3 (d) 2/15

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