Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 385 · 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) 5/6 (b) 2/3 (c) 1/3 (d) 1/4
2. 2.A bag has 8 red, 8 green and 9 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 18/25 (b) 8/25 (c) 1/3 (d) 17/25
3. 3.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/4 (b) 1/8 (c) 3/8 (d) 1/4
4. 4.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 1/11 (c) 3/11 (d) 1/9
5. 5.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
6. 6.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/12 (b) 1/11 (c) 2/11 (d) 1/18
8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/6 (b) 1/11 (c) 5/36 (d) 5/11
9. 9.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 3/4 (b) 1/3 (c) 1/4 (d) 1/2
10. 10.A bag has 9 blue, 4 red and 3 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/13 (b) 1/3 (c) 3/16 (d) 13/16
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/11 (b) 1/9 (c) 4/11 (d) 5/36
12. 12.A bag has 6 yellow, 7 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/11 (b) 1/3 (c) 8/11 (d) 3/8
13. 13.Two coins are tossed together. What is the probability of getting exactly one head? (a) 2/3 (b) 1/4 (c) 1/2 (d) 1/3
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 2/11 (b) 1/18 (c) 1/12 (d) 1/11
15. 15.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
16. 16.A bag has 3 white, 7 red and 2 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 7/12 (b) 2/3 (c) 1/3 (d) 5/12
17. 17.A bag has 8 green, 5 yellow and 5 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/13 (b) 5/18 (c) 1/3 (d) 13/18
18. 18.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/2 (b) 1/6 (c) 2/3 (d) 1/3
19. 19.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
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/9 (b) 3/11 (c) 1/11 (d) 1/12
21. 21.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
22. 22.A bag has 5 green, 5 red and 8 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 7/9 (b) 5/18 (c) 13/18 (d) 1/3
23. 23.A bag has 6 blue, 2 red and 8 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/5 (b) 1/3 (c) 5/8 (d) 3/8
24. 24.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/6 (b) 1/5 (c) 5/6 (d) 1/3
25. 25.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/8 (c) 1/7 (d) 7/8
26. 26.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/36 (b) 1/6 (c) 5/11 (d) 1/11
27. 27.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/8 (c) 7/8 (d) 3/8
28. 28.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
29. 29.A bag has 5 blue, 2 yellow and 2 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 4/9 (b) 2/3 (c) 5/9 (d) 1/3
30. 30.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
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 6/11 (b) 1/11 (c) 1/6 (d) 7/36
32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/11 (c) 1/12 (d) 1/36
33. 33.A bag has 8 green, 3 white and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 3/4 (b) 4/7 (c) 1/3 (d) 3/7
34. 34.A bag has 7 red, 3 white and 2 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 5/12 (c) 2/3 (d) 7/12
35. 35.A bag has 3 white, 2 yellow and 2 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 2/7 (b) 5/7 (c) 6/7 (d) 1/3
36. 36.A bag has 3 blue, 6 green and 2 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/11 (b) 6/11 (c) 7/11 (d) 1/3
37. 37.A bag has 2 blue, 7 white and 8 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 10/17 (b) 1/3 (c) 9/17 (d) 8/17
38. 38.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
39. 39.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/4 (b) 2/3 (c) 5/6 (d) 1/3
40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 5/36 (b) 1/9 (c) 4/11 (d) 1/11

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