Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 126 · 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, 2 yellow and 2 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 5/7 (c) 2/5 (d) 2/7
2. 2.A bag has 3 green, 9 yellow and 3 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 4/5 (b) 1/4 (c) 1/3 (d) 1/5
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 2/11 (b) 1/12 (c) 1/18 (d) 1/11
4. 4.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
5. 5.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
6. 6.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
7. 7.A bag has 2 white, 5 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 15/16 (b) 7/8 (c) 1/8 (d) 1/3
8. 8.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 1/3 (c) 2/3 (d) 1/2
9. 9.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 3/8 (c) 1/4 (d) 5/8
10. 10.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 3/11 (c) 1/12 (d) 1/11
11. 11.A bag has 8 red, 8 blue and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 8/21 (b) 1/3 (c) 2/3 (d) 13/21
12. 12.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/3 (b) 1/4 (c) 1/2 (d) 3/4
13. 13.A bag has 2 white, 4 yellow and 3 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 2/3 (b) 5/9 (c) 1/3 (d) 4/9
14. 14.A bag has 7 yellow, 6 red and 5 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 5/13 (b) 5/18 (c) 13/18 (d) 1/3
15. 15.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 2/3 (b) 1/3 (c) 1/4 (d) 5/6
16. 16.A bag has 4 red, 8 blue and 6 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/18 (b) 2/3 (c) 13/18 (d) 1/3
17. 17.A bag has 3 blue, 4 green and 9 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 13/16 (c) 3/16 (d) 7/8
18. 18.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 2/3 (c) 1/2 (d) 1/6
19. 19.A bag has 2 red, 2 green and 4 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 7/8 (b) 1/4 (c) 1/3 (d) 3/4
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/6 (b) 1/11 (c) 5/36 (d) 5/11
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/6 (b) 5/11 (c) 1/11 (d) 5/36
22. 22.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
23. 23.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
24. 24.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
25. 25.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
26. 26.A bag has 7 yellow, 3 white and 7 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 7/17 (b) 11/17 (c) 1/3 (d) 10/17
27. 27.A bag has 7 green, 9 yellow and 6 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 3/11 (b) 8/11 (c) 1/3 (d) 17/22
28. 28.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
29. 29.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/8 (b) 3/8 (c) 3/4 (d) 1/4
30. 30.A bag has 3 red, 7 green and 3 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 11/13 (b) 10/13 (c) 1/3 (d) 3/13
31. 31.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
32. 32.A bag has 5 green, 6 red and 2 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/8 (b) 1/3 (c) 5/13 (d) 8/13
33. 33.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
34. 34.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 7/8 (c) 1/8 (d) 1/7
35. 35.A bag has 3 red, 8 blue and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 13/16 (b) 1/3 (c) 3/16 (d) 7/8
36. 36.A bag has 7 blue, 2 yellow and 2 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 2/9 (b) 2/11 (c) 1/3 (d) 9/11
37. 37.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
38. 38.A bag has 5 red, 3 green and 2 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/10 (b) 1/3 (c) 3/10 (d) 3/7
39. 39.A bag has 7 blue, 7 green and 2 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 7/9 (c) 7/16 (d) 9/16
40. 40.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

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