Probability Worksheet for Class 8 Maths Olympiad

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

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