Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 49 · 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 number less than 4? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
2. 2.A bag has 6 blue, 8 green and 6 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/3 (b) 2/5 (c) 3/5 (d) 1/3
3. 3.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 3/8 (c) 1/8 (d) 3/4
4. 4.Two coins are tossed together. What is the probability of getting exactly one head? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/4
5. 5.A bag has 5 red, 4 yellow and 3 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/7 (b) 7/12 (c) 1/3 (d) 5/12
6. 6.A bag has 4 yellow, 5 red and 8 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 4/13 (b) 1/3 (c) 4/17 (d) 13/17
7. 7.A bag has 3 yellow, 2 red and 2 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/7 (b) 3/4 (c) 4/7 (d) 1/3
8. 8.A bag has 6 red, 8 yellow and 3 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/14 (b) 14/17 (c) 1/3 (d) 3/17
9. 9.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 4/11 (b) 5/36 (c) 1/11 (d) 1/9
10. 10.A bag has 6 white, 8 red and 2 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 11/16 (c) 5/8 (d) 3/8
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/11 (b) 1/6 (c) 5/36 (d) 5/11
12. 12.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 3/8 (c) 1/4 (d) 7/8
13. 13.A bag has 7 red, 2 blue and 5 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/7 (b) 1/3 (c) 1/6 (d) 6/7
14. 14.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
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 1/12 (c) 1/11 (d) 3/11
16. 16.Two coins are tossed together. What is the probability of getting at least one head? (a) 3/4 (b) 1/4 (c) 1/2 (d) 1/3
17. 17.A bag has 5 blue, 5 green and 4 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 9/14 (b) 5/7 (c) 5/14 (d) 1/3
18. 18.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 1/2 (c) 2/3 (d) 1/3
19. 19.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 2/3 (c) 1/2 (d) 1/3
20. 20.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/2 (b) 1/3 (c) 1/6 (d) 2/3
21. 21.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 2/3 (c) 1/4 (d) 5/6
22. 22.A bag has 3 green, 3 red and 7 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 3/13 (b) 11/13 (c) 10/13 (d) 1/3
23. 23.A bag has 8 yellow, 8 green and 6 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 7/11 (b) 15/22 (c) 1/3 (d) 4/11
24. 24.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 5/6 (b) 1/5 (c) 1/3 (d) 1/6
25. 25.A bag has 5 yellow, 8 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 9/16 (b) 1/16 (c) 1/3 (d) 1/2
26. 26.A bag has 2 yellow, 9 green and 2 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 12/13 (c) 11/13 (d) 2/13
27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/12 (c) 1/36 (d) 1/18
28. 28.A bag has 3 blue, 9 yellow and 7 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 17/19 (b) 1/3 (c) 3/19 (d) 16/19
29. 29.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
30. 30.A bag has 2 green, 4 white and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 8/9 (b) 1/3 (c) 7/9 (d) 2/9
31. 31.A bag has 8 red, 9 white and 7 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 17/24 (b) 2/3 (c) 1/3 (d) 1/24
32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 2/11 (c) 1/12 (d) 1/18
33. 33.A bag has 8 yellow, 9 red and 4 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 13/21 (c) 8/13 (d) 8/21
34. 34.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 4/11 (c) 1/11 (d) 1/9
35. 35.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 3/5 (c) 5/8 (d) 1/4
36. 36.A bag has 9 red, 7 green and 9 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/18 (b) 18/25 (c) 1/3 (d) 7/25
37. 37.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/11 (b) 5/11 (c) 1/6 (d) 5/36
38. 38.A bag has 7 white, 2 yellow and 7 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 7/16 (b) 9/16 (c) 1/3 (d) 5/8
39. 39.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
40. 40.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

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