Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 645 · 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 number less than 3? (a) 1/2 (b) 1/6 (c) 1/3 (d) 2/3
2. 2.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
3. 3.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/4
4. 4.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
5. 5.A bag has 2 green, 7 blue and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 11/12 (c) 1/6 (d) 5/6
6. 6.A bag has 2 yellow, 4 red and 9 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/5 (b) 2/5 (c) 2/3 (d) 1/3
7. 7.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
8. 8.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
9. 9.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 1/3 (c) 1/6 (d) 2/3
10. 10.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/7 (c) 7/8 (d) 1/8
11. 11.A bag has 8 yellow, 8 blue and 5 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 2/3 (b) 1/3 (c) 13/21 (d) 8/21
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/18 (b) 2/11 (c) 1/12 (d) 1/11
13. 13.Three coins are tossed together. What is the probability of getting at least one head? (a) 3/8 (b) 7/8 (c) 1/8 (d) 1/4
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 1/18 (c) 2/11 (d) 1/12
15. 15.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
16. 16.A bag has 5 green, 5 yellow and 5 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 2/3 (b) 11/15 (c) 1/3 (d) 1/15
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/36 (b) 1/12 (c) 1/11 (d) 1/18
18. 18.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
19. 19.A bag has 2 blue, 8 yellow and 3 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 10/13 (b) 3/13 (c) 1/3 (d) 11/13
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 5/36 (b) 1/11 (c) 4/11 (d) 1/9
21. 21.A bag has 3 green, 2 yellow and 5 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 3/7 (b) 3/10 (c) 7/10 (d) 1/3
22. 22.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
23. 23.A bag has 9 red, 2 green and 6 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 11/17 (b) 6/11 (c) 1/3 (d) 6/17
24. 24.A bag has 8 yellow, 7 white and 2 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 8/17 (c) 9/17 (d) 10/17
25. 25.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 1/4 (c) 1/3 (d) 3/4
26. 26.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/5 (b) 1/3 (c) 1/6 (d) 5/6
27. 27.A bag has 3 blue, 7 red and 7 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 3/17 (b) 15/17 (c) 1/3 (d) 14/17
28. 28.A bag has 8 red, 7 white and 6 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 8/21 (c) 13/21 (d) 2/3
29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/12 (c) 1/36 (d) 1/18
30. 30.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/2 (b) 3/4 (c) 1/3 (d) 1/4
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 4/11 (c) 1/9 (d) 1/11
32. 32.A bag has 2 yellow, 6 red and 5 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 11/13 (b) 2/11 (c) 1/3 (d) 2/13
33. 33.A bag has 6 green, 9 blue and 6 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 2/7 (b) 16/21 (c) 5/7 (d) 1/3
34. 34.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
35. 35.A bag has 7 red, 7 green and 9 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 7/23 (c) 7/16 (d) 16/23
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) 2/3 (d) 5/6
37. 37.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/3 (b) 1/5 (c) 1/6 (d) 5/6
38. 38.A bag has 3 yellow, 4 white and 5 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/4 (b) 1/3 (c) 1/12 (d) 3/4
39. 39.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
40. 40.A bag has 5 white, 2 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/5 (b) 1/3 (c) 8/15 (d) 7/15

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