Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 475 · 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 3 red, 6 yellow and 6 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 13/15 (b) 1/5 (c) 1/3 (d) 4/5
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/36 (b) 5/11 (c) 1/6 (d) 1/11
3. 3.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
4. 4.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 5/6 (b) 1/6 (c) 1/3 (d) 1/5
5. 5.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 7/8 (c) 1/8 (d) 3/8
6. 6.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 1/4 (c) 3/4 (d) 1/3
7. 7.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 1/4 (c) 1/3 (d) 2/3
8. 8.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
9. 9.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/11 (b) 1/11 (c) 5/36 (d) 1/6
10. 10.A bag has 3 blue, 9 white and 4 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 7/8 (b) 13/16 (c) 3/16 (d) 1/3
11. 11.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 2/3 (c) 1/4 (d) 1/3
12. 12.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
13. 13.A bag has 7 blue, 4 red and 6 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 7/10 (b) 1/3 (c) 10/17 (d) 7/17
14. 14.A bag has 7 green, 3 white and 9 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 12/19 (b) 7/19 (c) 1/3 (d) 13/19
15. 15.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/2 (c) 1/4 (d) 3/4
16. 16.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
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/18 (c) 1/12 (d) 1/36
18. 18.A bag has 2 red, 7 white and 5 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 5/9 (b) 1/3 (c) 9/14 (d) 5/14
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 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
21. 21.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
22. 22.A bag has 5 blue, 9 green and 8 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 9/13 (b) 13/22 (c) 1/3 (d) 9/22
23. 23.A bag has 7 red, 7 blue and 6 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 7/20 (b) 7/10 (c) 1/3 (d) 13/20
24. 24.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) 10/17 (b) 7/10 (c) 7/17 (d) 1/3
25. 25.A bag has 7 red, 4 yellow and 2 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/11 (b) 1/3 (c) 11/13 (d) 2/13
26. 26.A bag has 3 green, 9 red and 9 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 4/7 (b) 1/3 (c) 3/4 (d) 3/7
27. 27.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
28. 28.A bag has 5 green, 7 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 7/13 (b) 1/3 (c) 13/20 (d) 7/20
29. 29.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/7 (b) 7/8 (c) 1/8 (d) 1/4
30. 30.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 2/11 (b) 1/11 (c) 1/18 (d) 1/12
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/11 (b) 7/36 (c) 6/11 (d) 1/6
32. 32.A bag has 3 yellow, 2 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 3/14 (c) 11/14 (d) 6/7
33. 33.A bag has 9 red, 8 blue and 3 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/5 (b) 2/3 (c) 2/5 (d) 1/3
34. 34.A bag has 8 white, 8 blue and 2 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/9 (b) 1/3 (c) 4/5 (d) 4/9
35. 35.A bag has 4 white, 6 yellow and 8 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 4/9 (b) 4/5 (c) 5/9 (d) 1/3
36. 36.A bag has 4 blue, 2 red and 3 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 4/5 (b) 4/9 (c) 5/9 (d) 1/3
37. 37.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
38. 38.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 2/11 (b) 1/11 (c) 1/12 (d) 1/18
39. 39.A bag has 4 white, 9 green and 2 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/5 (b) 1/3 (c) 3/5 (d) 2/3
40. 40.A bag has 2 green, 8 white and 5 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 11/15 (c) 1/15 (d) 2/3

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