Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 303 · 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 2 white, 5 red and 2 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 5/9 (b) 4/5 (c) 1/3 (d) 4/9
2. 2.A bag has 7 green, 3 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 12/19 (b) 1/3 (c) 7/12 (d) 7/19
3. 3.A bag has 7 red, 2 blue and 7 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 9/16 (c) 7/16 (d) 7/9
4. 4.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 1/4 (c) 5/8 (d) 3/5
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 1/11 (c) 2/11 (d) 1/18
6. 6.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 1/6 (c) 1/3 (d) 2/3
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/36 (b) 5/11 (c) 1/11 (d) 1/6
8. 8.A bag has 9 white, 9 red and 5 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 9/23 (b) 9/14 (c) 1/3 (d) 14/23
9. 9.A bag has 3 blue, 6 yellow and 4 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 9/13 (c) 4/13 (d) 4/9
10. 10.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 1/3 (c) 1/4 (d) 2/3
11. 11.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/3 (c) 1/2 (d) 3/4
12. 12.A bag has 3 white, 9 green and 8 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/20 (b) 1/3 (c) 17/20 (d) 3/17
13. 13.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
14. 14.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
15. 15.A bag has 7 yellow, 8 white and 9 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 17/24 (b) 1/3 (c) 7/24 (d) 3/4
16. 16.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
17. 17.A bag has 8 yellow, 7 green and 7 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 15/22 (b) 7/15 (c) 1/3 (d) 7/22
18. 18.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/12 (b) 2/11 (c) 1/18 (d) 1/11
19. 19.A bag has 5 white, 9 blue and 8 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 9/13 (c) 9/22 (d) 13/22
20. 20.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/3 (b) 1/4 (c) 5/6 (d) 2/3
21. 21.A bag has 8 red, 5 white and 8 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 2/3 (b) 8/21 (c) 13/21 (d) 1/3
22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/12 (b) 1/18 (c) 1/36 (d) 1/11
23. 23.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
24. 24.A bag has 3 green, 4 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/3 (b) 3/5 (c) 1/3 (d) 2/5
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/36 (c) 1/12 (d) 1/11
26. 26.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 3/8 (c) 7/8 (d) 1/8
27. 27.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
28. 28.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
29. 29.A bag has 6 yellow, 8 white and 7 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 16/21 (b) 5/7 (c) 2/7 (d) 1/3
30. 30.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
31. 31.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
32. 32.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
33. 33.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/12 (b) 1/9 (c) 1/11 (d) 3/11
34. 34.A bag has 6 green, 3 red and 7 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 11/16 (b) 5/8 (c) 3/8 (d) 1/3
35. 35.A bag has 8 yellow, 5 blue and 8 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/16 (b) 1/3 (c) 16/21 (d) 5/21
36. 36.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 2/3 (b) 1/3 (c) 5/6 (d) 1/4
37. 37.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 4/11 (b) 1/11 (c) 1/9 (d) 5/36
38. 38.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
39. 39.A bag has 2 white, 6 blue and 2 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/5 (b) 4/5 (c) 1/3 (d) 1/4
40. 40.A bag has 8 yellow, 3 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 3/11 (c) 11/14 (d) 3/14

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