Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 548 · 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 a factor of 6? (a) 2/3 (b) 5/6 (c) 1/4 (d) 1/3
2. 2.A bag has 4 red, 2 blue and 7 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 7/13 (b) 6/7 (c) 6/13 (d) 1/3
3. 3.A bag has 4 green, 4 red and 5 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 5/13 (b) 1/3 (c) 9/13 (d) 8/13
4. 4.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
5. 5.A bag has 6 green, 3 white and 8 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 8/17 (b) 1/3 (c) 9/17 (d) 8/9
6. 6.A bag has 2 green, 7 white and 8 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 11/17 (b) 7/17 (c) 10/17 (d) 1/3
7. 7.A bag has 8 red, 9 white and 5 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 17/22 (b) 5/22 (c) 1/3 (d) 5/17
8. 8.A bag has 6 white, 5 yellow and 8 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 8/11 (b) 11/19 (c) 8/19 (d) 1/3
9. 9.A bag has 3 blue, 2 red and 6 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/8 (b) 8/11 (c) 3/11 (d) 1/3
10. 10.A bag has 7 green, 8 yellow and 7 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 15/22 (c) 7/15 (d) 7/22
11. 11.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/11 (b) 1/6 (c) 5/36 (d) 1/11
13. 13.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/3 (b) 2/3 (c) 5/6 (d) 1/4
14. 14.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
15. 15.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
16. 16.A bag has 9 blue, 5 red and 3 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 12/17 (b) 5/17 (c) 5/12 (d) 1/3
17. 17.A bag has 7 green, 6 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 15/22 (b) 7/15 (c) 1/3 (d) 7/22
18. 18.A bag has 2 green, 8 yellow and 8 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/8 (b) 8/9 (c) 1/9 (d) 1/3
19. 19.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
20. 20.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 1/2 (c) 2/3 (d) 1/3
21. 21.A bag has 3 yellow, 8 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 2/5 (c) 3/5 (d) 13/20
22. 22.A bag has 9 white, 7 yellow and 7 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 14/23 (c) 9/14 (d) 9/23
23. 23.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/12 (b) 1/18 (c) 1/36 (d) 1/11
24. 24.A bag has 2 yellow, 5 green and 2 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/9 (b) 2/9 (c) 1/3 (d) 2/7
25. 25.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
26. 26.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 7/36 (c) 6/11 (d) 1/11
27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 5/36 (b) 1/9 (c) 1/11 (d) 4/11
28. 28.A bag has 4 white, 7 red and 7 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 11/18 (c) 7/18 (d) 7/11
29. 29.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/4 (b) 1/4 (c) 3/8 (d) 1/8
30. 30.A bag has 4 white, 9 red and 3 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 9/16 (b) 1/3 (c) 7/9 (d) 7/16
31. 31.A bag has 2 green, 7 yellow and 4 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/13 (b) 1/3 (c) 8/13 (d) 6/13
32. 32.A bag has 8 blue, 5 green and 6 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 5/19 (b) 15/19 (c) 14/19 (d) 1/3
33. 33.A bag has 3 yellow, 7 white and 7 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/17 (b) 1/3 (c) 3/14 (d) 14/17
34. 34.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
35. 35.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
36. 36.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 2/3 (c) 1/3 (d) 1/2
37. 37.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/5 (b) 1/3 (c) 1/6 (d) 5/6
38. 38.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/4
39. 39.A bag has 8 red, 8 white and 7 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 8/15 (b) 1/3 (c) 8/23 (d) 15/23
40. 40.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

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