Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 656 · 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.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/36 (b) 1/18 (c) 1/11 (d) 1/12
2. 2.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 5/6 (c) 1/4 (d) 1/3
3. 3.A bag has 4 green, 7 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 4/7 (c) 1/14 (d) 1/2
4. 4.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 1/2 (c) 2/3 (d) 1/3
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/11 (b) 1/6 (c) 5/11 (d) 5/36
6. 6.A bag has 8 blue, 6 yellow and 6 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 13/20 (c) 2/5 (d) 3/5
7. 7.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/5 (c) 5/8 (d) 3/8
8. 8.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
9. 9.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
10. 10.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/9 (b) 5/36 (c) 1/11 (d) 4/11
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/9 (b) 3/11 (c) 1/12 (d) 1/11
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/11 (b) 6/11 (c) 7/36 (d) 1/6
13. 13.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 3/4 (c) 1/2 (d) 1/3
14. 14.A bag has 9 blue, 4 yellow and 5 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 7/9 (b) 1/3 (c) 5/18 (d) 13/18
15. 15.Two coins are tossed together. What is the probability of getting at least one head? (a) 3/4 (b) 1/3 (c) 1/2 (d) 1/4
16. 16.A bag has 7 yellow, 6 blue and 5 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/13 (b) 5/18 (c) 13/18 (d) 1/3
17. 17.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 3/8 (c) 7/8 (d) 1/4
18. 18.A bag has 6 green, 3 red and 4 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 9/13 (b) 1/3 (c) 4/13 (d) 4/9
19. 19.A bag has 6 white, 9 blue and 6 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 4/7 (b) 3/7 (c) 13/21 (d) 1/3
20. 20.A bag has 4 green, 3 yellow and 7 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/14 (b) 1/3 (c) 3/11 (d) 11/14
21. 21.A bag has 8 blue, 4 white and 2 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 2/7 (b) 1/3 (c) 5/7 (d) 11/14
22. 22.A bag has 3 blue, 6 white and 7 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 3/16 (b) 13/16 (c) 7/8 (d) 1/3
23. 23.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
24. 24.A bag has 4 green, 7 white and 9 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 9/11 (b) 1/3 (c) 11/20 (d) 9/20
25. 25.A bag has 9 green, 2 yellow and 2 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 11/13 (c) 2/11 (d) 2/13
26. 26.A bag has 6 red, 5 yellow and 2 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 8/13 (c) 5/13 (d) 5/8
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.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 1/11 (c) 1/6 (d) 5/36
29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/11 (b) 1/12 (c) 1/18 (d) 2/11
30. 30.A bag has 4 white, 6 red and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 10/13 (b) 4/13 (c) 9/13 (d) 1/3
31. 31.A bag has 8 yellow, 7 blue and 8 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 15/23 (b) 1/3 (c) 16/23 (d) 8/23
32. 32.A bag has 9 red, 9 white and 5 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/18 (b) 5/23 (c) 18/23 (d) 1/3
33. 33.A bag has 5 red, 5 green and 4 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/14 (b) 9/14 (c) 5/9 (d) 1/3
34. 34.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 2/3 (c) 1/2 (d) 1/6
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 1/11 (c) 4/11 (d) 1/9
36. 36.A bag has 2 blue, 5 white and 6 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 12/13 (b) 2/13 (c) 11/13 (d) 1/3
37. 37.A bag has 2 green, 6 red and 2 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/5 (b) 1/3 (c) 7/10 (d) 2/5
38. 38.A bag has 2 yellow, 7 green and 8 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/17 (b) 1/3 (c) 7/10 (d) 10/17
39. 39.A bag has 5 blue, 4 green and 3 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 5/12 (b) 1/3 (c) 7/12 (d) 2/3
40. 40.A bag has 6 white, 7 yellow and 2 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 13/15 (b) 2/15 (c) 14/15 (d) 1/3

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