Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 511 · 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 factor of 6? (a) 1/3 (b) 1/4 (c) 2/3 (d) 5/6
2. 2.A bag has 2 green, 3 yellow and 6 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/9 (b) 1/3 (c) 9/11 (d) 2/11
3. 3.A bag has 2 red, 3 blue and 8 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/11 (b) 2/13 (c) 1/3 (d) 11/13
4. 4.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
5. 5.A bag has 8 red, 9 green and 8 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 8/25 (b) 17/25 (c) 18/25 (d) 1/3
6. 6.A bag has 6 green, 5 white and 8 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 13/19 (c) 6/19 (d) 14/19
7. 7.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 2/3 (b) 1/3 (c) 5/6 (d) 1/4
8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/36 (c) 1/18 (d) 1/12
9. 9.A bag has 3 white, 4 red and 3 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/5 (b) 1/3 (c) 2/5 (d) 2/3
10. 10.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
11. 11.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
12. 12.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/3 (c) 3/4 (d) 1/2
13. 13.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 3/8 (c) 1/4 (d) 7/8
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 3/11 (b) 1/9 (c) 1/12 (d) 1/11
15. 15.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/11 (b) 2/11 (c) 1/12 (d) 1/18
17. 17.A bag has 7 green, 2 blue and 5 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/2 (b) 1/3 (c) 1/14 (d) 4/7
18. 18.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/11 (b) 1/6 (c) 5/11 (d) 5/36
19. 19.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
20. 20.A bag has 3 white, 8 yellow and 8 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 3/19 (c) 17/19 (d) 16/19
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 1/12 (c) 2/11 (d) 1/18
22. 22.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
23. 23.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/8 (b) 3/4 (c) 3/8 (d) 1/4
24. 24.A bag has 8 red, 2 white and 8 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 4/5 (b) 1/3 (c) 5/9 (d) 4/9
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 1/11 (c) 5/36 (d) 1/6
26. 26.A bag has 4 green, 7 white and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 16/19 (c) 15/19 (d) 4/19
27. 27.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
28. 28.A bag has 6 white, 5 blue and 2 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 8/13 (c) 7/13 (d) 6/13
29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 4/11 (b) 1/9 (c) 5/36 (d) 1/11
30. 30.A bag has 6 blue, 3 white and 7 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/8 (b) 3/8 (c) 3/5 (d) 1/3
31. 31.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/4 (b) 1/3 (c) 5/6 (d) 2/3
32. 32.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/6 (b) 1/2 (c) 2/3 (d) 1/3
33. 33.A bag has 4 red, 7 blue and 6 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 10/17 (b) 7/17 (c) 11/17 (d) 1/3
34. 34.A bag has 7 green, 3 blue and 6 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 7/8 (c) 13/16 (d) 3/16
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 7/36 (b) 6/11 (c) 1/11 (d) 1/6
36. 36.A bag has 8 green, 5 red and 2 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 11/15 (b) 1/15 (c) 1/3 (d) 2/3
37. 37.A bag has 5 yellow, 4 blue and 4 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 4/9 (b) 1/3 (c) 4/13 (d) 9/13
38. 38.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
39. 39.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 2/3 (c) 1/2 (d) 1/3
40. 40.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/5 (c) 5/8 (d) 3/8

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