Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 289 · 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 7 white, 4 yellow and 2 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) 6/7
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.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
4. 4.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
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 3/11 (b) 1/11 (c) 1/12 (d) 1/9
6. 6.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
7. 7.A bag has 6 white, 6 red and 2 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 3/4 (c) 3/7 (d) 4/7
8. 8.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 1/4 (c) 5/8 (d) 3/5
9. 9.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/9 (c) 1/11 (d) 1/12
10. 10.A bag has 3 green, 6 yellow and 5 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 3/14 (b) 1/3 (c) 11/14 (d) 6/7
11. 11.Two coins are tossed together. What is the probability of getting exactly one head? (a) 2/3 (b) 1/4 (c) 1/2 (d) 1/3
12. 12.A bag has 8 blue, 8 yellow and 6 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/11 (b) 1/3 (c) 4/7 (d) 4/11
13. 13.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) 1/4 (d) 1/8
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/18 (b) 1/11 (c) 1/12 (d) 1/36
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 1/11 (c) 2/11 (d) 1/18
16. 16.A bag has 6 blue, 4 yellow and 4 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 5/7 (b) 2/5 (c) 2/7 (d) 1/3
17. 17.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
18. 18.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
19. 19.A bag has 6 green, 5 blue and 4 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 2/5 (c) 3/5 (d) 2/3
20. 20.A bag has 7 green, 5 white and 9 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 5/21 (b) 16/21 (c) 1/3 (d) 5/16
21. 21.A bag has 9 red, 5 green and 7 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/2 (b) 1/3 (c) 8/21 (d) 2/3
22. 22.A bag has 5 red, 7 blue and 8 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 7/10 (c) 13/20 (d) 7/20
23. 23.A bag has 6 yellow, 7 green and 6 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 13/19 (c) 14/19 (d) 6/19
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 4/11 (b) 1/11 (c) 5/36 (d) 1/9
25. 25.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
26. 26.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 4/11 (c) 1/11 (d) 1/9
27. 27.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
28. 28.A bag has 8 green, 2 yellow and 4 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 6/7 (b) 1/3 (c) 1/6 (d) 1/7
29. 29.A bag has 3 red, 2 white and 7 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/4 (b) 3/4 (c) 1/3 (d) 5/6
30. 30.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/3 (b) 1/6 (c) 5/6 (d) 1/5
31. 31.Two coins are tossed together. What is the probability of getting at least one head? (a) 3/4 (b) 1/3 (c) 1/4 (d) 1/2
32. 32.Three coins are tossed together. What is the probability of getting at least one head? (a) 7/8 (b) 1/4 (c) 3/8 (d) 1/8
33. 33.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 2/3 (c) 1/2 (d) 1/3
34. 34.A bag has 9 blue, 7 yellow and 7 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 14/23 (b) 1/3 (c) 9/14 (d) 9/23
35. 35.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
36. 36.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/3 (b) 2/3 (c) 5/6 (d) 1/4
37. 37.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/6 (b) 5/11 (c) 5/36 (d) 1/11
38. 38.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
39. 39.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/18 (b) 1/11 (c) 1/12 (d) 2/11
40. 40.A bag has 4 yellow, 6 blue and 4 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 4/7 (c) 9/14 (d) 3/7

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