Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 373 · 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) 2/3 (b) 1/3 (c) 5/6 (d) 1/4
2. 2.A bag has 8 blue, 4 green and 8 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/3 (b) 2/5 (c) 3/5 (d) 1/3
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 1/11 (c) 1/18 (d) 2/11
4. 4.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/12 (b) 2/11 (c) 1/11 (d) 1/18
5. 5.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 1/3 (c) 1/2 (d) 2/3
6. 6.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/2 (c) 3/4 (d) 1/4
7. 7.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 5/8 (c) 3/5 (d) 1/4
8. 8.A bag has 6 blue, 2 green and 3 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/11 (b) 6/11 (c) 1/3 (d) 7/11
9. 9.A bag has 5 red, 8 white and 2 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/15 (b) 1/3 (c) 13/15 (d) 2/13
10. 10.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
11. 11.A bag has 8 red, 7 green and 7 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/15 (b) 7/22 (c) 1/3 (d) 15/22
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 1/6 (c) 5/36 (d) 1/11
13. 13.A bag has 3 blue, 7 yellow and 4 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 11/14 (b) 1/3 (c) 3/11 (d) 3/14
14. 14.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 2/3 (b) 1/4 (c) 1/3 (d) 1/2
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/18 (c) 1/12 (d) 1/36
16. 16.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
17. 17.A bag has 7 red, 2 white and 5 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/9 (b) 9/14 (c) 1/3 (d) 5/14
18. 18.A bag has 5 blue, 2 white and 4 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/6 (b) 1/3 (c) 5/11 (d) 6/11
19. 19.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
20. 20.A bag has 8 red, 2 white and 2 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 5/6 (b) 1/3 (c) 11/12 (d) 1/6
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 6/11 (b) 1/6 (c) 7/36 (d) 1/11
22. 22.A bag has 3 green, 2 white and 6 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 9/11 (b) 2/11 (c) 1/3 (d) 10/11
23. 23.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/8 (c) 1/7 (d) 1/4
24. 24.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 5/6 (b) 1/4 (c) 1/3 (d) 2/3
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/12 (b) 1/11 (c) 1/18 (d) 1/36
26. 26.A bag has 7 white, 3 red and 5 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 4/5 (b) 1/3 (c) 1/5 (d) 13/15
27. 27.A bag has 2 yellow, 8 green and 9 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 9/19 (b) 10/19 (c) 9/10 (d) 1/3
28. 28.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
29. 29.A bag has 3 white, 2 blue and 5 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 3/5 (c) 1/2 (d) 1/10
30. 30.A bag has 9 green, 3 blue and 7 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 9/10 (c) 10/19 (d) 9/19
31. 31.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
32. 32.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
33. 33.A bag has 6 blue, 7 green and 8 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 8/21 (b) 1/3 (c) 1/2 (d) 2/3
34. 34.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 5/6 (b) 1/5 (c) 1/6 (d) 1/3
35. 35.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/3 (b) 5/6 (c) 2/3 (d) 1/4
36. 36.A bag has 5 white, 8 yellow and 2 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 7/8 (b) 1/3 (c) 8/15 (d) 7/15
37. 37.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
38. 38.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/6 (b) 1/2 (c) 2/3 (d) 1/3
39. 39.A bag has 5 white, 6 yellow and 8 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 13/19 (c) 6/13 (d) 6/19
40. 40.A bag has 5 green, 2 yellow and 8 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 2/3 (c) 2/5 (d) 1/2

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