Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 297 · 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 8 green, 9 red and 9 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 9/13 (b) 9/26 (c) 1/3 (d) 17/26
2. 2.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/7 (c) 1/8 (d) 1/4
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 3/11 (c) 1/11 (d) 1/12
4. 4.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
5. 5.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/8 (c) 3/8 (d) 7/8
6. 6.A bag has 5 green, 8 red and 2 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 7/15 (c) 8/15 (d) 3/5
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/36 (b) 1/18 (c) 1/12 (d) 1/11
8. 8.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
9. 9.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 1/3 (c) 1/4 (d) 2/3
10. 10.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/3 (b) 1/5 (c) 5/6 (d) 1/6
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 7/36 (b) 1/11 (c) 6/11 (d) 1/6
12. 12.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
13. 13.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 2/3 (b) 1/3 (c) 5/6 (d) 1/4
14. 14.A bag has 6 white, 4 yellow and 5 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 3/5 (c) 2/5 (d) 2/3
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 1/11 (c) 1/9 (d) 4/11
16. 16.A bag has 3 green, 7 yellow and 8 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 7/18 (c) 2/3 (d) 11/18
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/11 (b) 1/18 (c) 2/11 (d) 1/12
18. 18.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/12 (b) 1/9 (c) 3/11 (d) 1/11
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 2 blue, 5 red and 8 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/5 (b) 1/3 (c) 7/15 (d) 8/15
21. 21.A bag has 2 yellow, 3 green and 3 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 5/8 (b) 3/4 (c) 3/8 (d) 1/3
22. 22.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/2 (c) 3/4 (d) 1/3
23. 23.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 1/8 (c) 3/8 (d) 3/4
24. 24.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 5/8 (c) 1/4 (d) 3/5
25. 25.A bag has 9 red, 2 white and 5 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 9/16 (c) 7/16 (d) 7/9
26. 26.A bag has 8 yellow, 9 white and 6 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 8/15 (b) 15/23 (c) 1/3 (d) 8/23
27. 27.A bag has 5 white, 9 red and 5 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 9/19 (b) 11/19 (c) 10/19 (d) 1/3
28. 28.A bag has 9 green, 6 white and 3 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/6 (b) 1/3 (c) 1/6 (d) 1/5
29. 29.A bag has 6 green, 6 blue and 2 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 9/14 (b) 1/3 (c) 4/7 (d) 3/7
30. 30.A bag has 2 yellow, 3 red and 5 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/5 (b) 1/3 (c) 4/5 (d) 9/10
31. 31.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
32. 32.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) 1/2 (d) 1/3
33. 33.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/36 (b) 5/11 (c) 1/6 (d) 1/11
34. 34.A bag has 6 yellow, 6 blue 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
35. 35.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 5/6 (b) 1/3 (c) 1/6 (d) 1/5
36. 36.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 1/3 (c) 1/4 (d) 5/6
37. 37.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/6 (b) 5/36 (c) 5/11 (d) 1/11
38. 38.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
39. 39.A bag has 8 green, 7 blue and 2 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 10/17 (c) 7/17 (d) 7/10
40. 40.A bag has 3 green, 4 red and 2 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 2/3 (c) 1/9 (d) 7/9

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