Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 709 · 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 an even number? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/9 (b) 4/11 (c) 5/36 (d) 1/11
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/12 (c) 1/18 (d) 1/36
4. 4.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/3 (b) 2/3 (c) 1/4 (d) 1/2
5. 5.A bag has 5 blue, 5 red and 5 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 2/3 (c) 11/15 (d) 1/15
6. 6.A bag has 6 green, 3 red and 3 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 7/12 (c) 1/2 (d) 1/12
7. 7.A bag has 3 red, 4 green and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 8/15 (b) 7/15 (c) 7/8 (d) 1/3
8. 8.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 1/3 (c) 2/3 (d) 1/4
9. 9.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
10. 10.A bag has 8 yellow, 6 red and 6 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/7 (b) 3/10 (c) 1/3 (d) 7/10
11. 11.A bag has 5 yellow, 6 white and 8 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 14/19 (b) 1/3 (c) 5/14 (d) 5/19
12. 12.A bag has 8 red, 5 blue and 2 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 7/8 (b) 1/3 (c) 7/15 (d) 8/15
13. 13.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
14. 14.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
15. 15.A bag has 2 blue, 3 red and 3 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/8 (b) 1/3 (c) 3/4 (d) 5/8
16. 16.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 7/8 (c) 1/4 (d) 3/8
17. 17.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/4
18. 18.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/36 (c) 1/18 (d) 1/12
19. 19.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/11 (b) 3/11 (c) 1/9 (d) 1/12
20. 20.A bag has 2 green, 5 yellow and 2 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 8/9 (b) 2/9 (c) 1/3 (d) 7/9
21. 21.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
22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/11 (b) 5/11 (c) 1/6 (d) 5/36
23. 23.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
24. 24.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
25. 25.A bag has 2 red, 9 white and 9 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/10 (b) 1/3 (c) 9/10 (d) 1/9
26. 26.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/8 (c) 5/8 (d) 3/5
27. 27.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/8 (b) 7/8 (c) 1/7 (d) 1/4
28. 28.A bag has 5 blue, 6 red and 2 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 7/13 (b) 8/13 (c) 6/13 (d) 1/3
29. 29.A bag has 5 white, 4 yellow and 8 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 13/17 (b) 4/13 (c) 1/3 (d) 4/17
30. 30.A bag has 5 red, 5 yellow and 9 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 5/19 (b) 14/19 (c) 1/3 (d) 15/19
31. 31.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/3 (b) 1/4 (c) 2/3 (d) 5/6
32. 32.A bag has 9 green, 6 white and 3 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 5/6 (b) 8/9 (c) 1/3 (d) 1/6
33. 33.A bag has 5 yellow, 7 blue and 2 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 6/7 (b) 1/7 (c) 1/3 (d) 1/6
34. 34.A bag has 7 white, 2 blue and 9 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 7/11 (b) 7/18 (c) 1/3 (d) 11/18
35. 35.A bag has 4 red, 6 yellow and 3 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 4/13 (c) 9/13 (d) 4/9
36. 36.A bag has 2 green, 9 yellow and 2 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 11/13 (b) 1/3 (c) 2/13 (d) 12/13
37. 37.A bag has 9 yellow, 9 red and 3 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 19/21 (c) 6/7 (d) 1/7
38. 38.A bag has 8 red, 8 yellow and 5 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 8/21 (b) 1/3 (c) 2/3 (d) 13/21
39. 39.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 2/11 (b) 1/18 (c) 1/11 (d) 1/12
40. 40.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) 3/4 (d) 3/8

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