Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 72 · 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) 1/6 (c) 1/3 (d) 2/3
2. 2.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 1/3 (c) 1/6 (d) 2/3
3. 3.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
4. 4.A bag has 4 red, 2 green and 7 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 7/13 (b) 1/3 (c) 8/13 (d) 6/13
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 1/11 (c) 1/12 (d) 3/11
6. 6.A bag has 2 red, 6 blue and 5 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 6/7 (b) 6/13 (c) 7/13 (d) 1/3
7. 7.Three coins are tossed together. What is the probability of getting at least one head? (a) 7/8 (b) 1/8 (c) 3/8 (d) 1/4
8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 5/36 (b) 4/11 (c) 1/11 (d) 1/9
9. 9.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/9 (b) 1/11 (c) 4/11 (d) 5/36
10. 10.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 1/4 (c) 2/3 (d) 1/3
11. 11.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/8 (c) 7/8 (d) 1/7
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/12 (b) 3/11 (c) 1/9 (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) 5/6 (c) 1/4 (d) 2/3
14. 14.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/3 (b) 5/6 (c) 1/6 (d) 1/5
15. 15.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
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/6 (b) 1/11 (c) 5/11 (d) 5/36
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/36 (b) 1/6 (c) 1/11 (d) 5/11
18. 18.A bag has 3 yellow, 7 blue and 7 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 15/17 (b) 1/3 (c) 14/17 (d) 3/17
19. 19.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
20. 20.A bag has 6 white, 4 green and 2 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 11/12 (b) 5/6 (c) 1/3 (d) 1/6
21. 21.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
22. 22.A bag has 7 red, 8 white and 2 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 8/17 (b) 1/3 (c) 9/17 (d) 10/17
23. 23.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 2/11 (b) 1/11 (c) 1/12 (d) 1/18
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/12 (c) 1/18 (d) 1/36
25. 25.A bag has 7 green, 4 red and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 4/5 (b) 1/3 (c) 11/15 (d) 4/15
26. 26.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
27. 27.A bag has 3 blue, 3 white and 9 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 3/5 (b) 1/3 (c) 2/3 (d) 2/5
28. 28.Two coins are tossed together. What is the probability of getting at least one head? (a) 3/4 (b) 1/4 (c) 1/3 (d) 1/2
29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/18 (b) 2/11 (c) 1/11 (d) 1/12
30. 30.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
31. 31.Two coins are tossed together. What is the probability of getting exactly one head? (a) 2/3 (b) 1/4 (c) 1/3 (d) 1/2
32. 32.A bag has 9 green, 3 white and 9 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 4/7 (b) 3/4 (c) 3/7 (d) 1/3
33. 33.A bag has 8 red, 8 green and 7 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 15/23 (b) 1/3 (c) 8/23 (d) 16/23
34. 34.A bag has 3 white, 6 green and 9 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 13/18 (c) 1/18 (d) 2/3
35. 35.A bag has 6 green, 8 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 6/17 (c) 6/11 (d) 11/17
36. 36.A bag has 5 blue, 4 red and 4 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 9/13 (c) 4/13 (d) 4/9
37. 37.A bag has 2 red, 2 white and 5 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/7 (b) 2/9 (c) 7/9 (d) 1/3
38. 38.A bag has 5 green, 8 yellow and 9 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 4/7 (b) 4/11 (c) 7/11 (d) 1/3
39. 39.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/8 (b) 1/8 (c) 1/4 (d) 3/4
40. 40.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 2/3 (b) 5/6 (c) 1/4 (d) 1/3

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