Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 250 · 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) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
2. 2.A bag has 5 blue, 6 white and 6 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 6/17 (c) 11/17 (d) 6/11
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/36 (b) 1/12 (c) 1/11 (d) 1/18
4. 4.A bag has 3 blue, 9 yellow and 4 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/4 (b) 5/16 (c) 1/4 (d) 1/3
5. 5.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
6. 6.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 2/3 (c) 1/2 (d) 1/6
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/6 (b) 5/36 (c) 1/11 (d) 5/11
8. 8.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
9. 9.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
10. 10.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/5 (b) 1/3 (c) 5/6 (d) 1/6
11. 11.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
12. 12.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
13. 13.A bag has 8 white, 9 yellow and 2 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 9/19 (b) 10/19 (c) 1/3 (d) 11/19
14. 14.A bag has 9 yellow, 2 red and 6 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 6/17 (b) 12/17 (c) 11/17 (d) 1/3
15. 15.A bag has 3 blue, 2 red and 9 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 1/7 (c) 1/6 (d) 6/7
16. 16.Three coins are tossed together. What is the probability of getting exactly one head? (a) 5/8 (b) 3/5 (c) 1/4 (d) 3/8
17. 17.A bag has 3 red, 9 yellow and 6 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 2/3 (c) 1/2 (d) 7/18
18. 18.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) 1/4 (d) 3/4
19. 19.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/9 (b) 5/36 (c) 4/11 (d) 1/11
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/12 (c) 1/9 (d) 1/11
21. 21.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
22. 22.A bag has 9 blue, 3 green and 5 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 8/9 (c) 9/17 (d) 8/17
23. 23.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/7 (c) 1/8 (d) 1/4
24. 24.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 1/4 (c) 1/3 (d) 2/3
25. 25.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
26. 26.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 4/11 (b) 5/36 (c) 1/9 (d) 1/11
27. 27.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/4 (b) 2/3 (c) 1/3 (d) 5/6
28. 28.A bag has 9 white, 2 yellow and 8 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 10/19 (b) 11/19 (c) 9/19 (d) 1/3
29. 29.A bag has 4 green, 5 blue and 4 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 4/13 (b) 1/3 (c) 9/13 (d) 4/9
30. 30.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 1/3 (c) 3/4 (d) 1/4
31. 31.A bag has 7 yellow, 2 red and 5 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 6/7 (b) 1/3 (c) 1/7 (d) 13/14
32. 32.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
33. 33.A bag has 3 blue, 2 red and 9 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 5/14 (c) 9/14 (d) 5/7
34. 34.A bag has 3 white, 7 red and 4 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/2 (b) 1/14 (c) 1/3 (d) 4/7
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 2/11 (c) 1/18 (d) 1/12
36. 36.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 1/9 (c) 3/11 (d) 1/11
37. 37.A bag has 8 green, 4 white and 5 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 9/17 (b) 8/17 (c) 1/3 (d) 10/17
38. 38.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 3/8 (c) 1/8 (d) 7/8
39. 39.A bag has 8 white, 8 yellow and 2 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 8/9 (b) 1/9 (c) 17/18 (d) 1/3
40. 40.A bag has 5 blue, 9 white and 8 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 13/22 (c) 7/11 (d) 9/22

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