Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 261 · 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 7 green, 3 red and 5 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 7/15 (b) 1/3 (c) 3/5 (d) 8/15
2. 2.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 5/8 (c) 3/8 (d) 1/4
3. 3.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
4. 4.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 5/6 (c) 1/4 (d) 1/3
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/18 (b) 1/12 (c) 1/11 (d) 2/11
6. 6.A fair dice is rolled once. What is the probability of getting an even number? (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 11? (a) 2/11 (b) 1/11 (c) 1/18 (d) 1/12
8. 8.A bag has 8 yellow, 7 red and 8 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 15/23 (b) 8/15 (c) 1/3 (d) 8/23
9. 9.A bag has 9 red, 2 green and 9 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 9/11 (c) 9/20 (d) 11/20
10. 10.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/5 (b) 5/6 (c) 1/6 (d) 1/3
11. 11.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 2/3 (b) 1/4 (c) 1/3 (d) 1/2
12. 12.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
13. 13.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
14. 14.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/4 (c) 1/2 (d) 3/4
15. 15.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
16. 16.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/3 (b) 5/6 (c) 1/6 (d) 1/5
17. 17.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) 3/4 (d) 1/4
18. 18.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
19. 19.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
20. 20.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/11 (b) 1/11 (c) 1/6 (d) 5/36
22. 22.A bag has 3 yellow, 2 green and 7 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/12 (b) 3/4 (c) 1/3 (d) 1/4
23. 23.A bag has 9 green, 4 yellow and 3 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/8 (b) 7/16 (c) 1/3 (d) 9/16
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/11 (b) 1/6 (c) 5/11 (d) 5/36
25. 25.A bag has 8 red, 2 green and 9 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 2/19 (c) 17/19 (d) 2/17
26. 26.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
27. 27.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/7 (c) 7/8 (d) 1/8
28. 28.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/4
29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 3/11 (c) 1/9 (d) 1/11
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.Three coins are tossed together. What is the probability of getting at least one head? (a) 7/8 (b) 1/4 (c) 3/8 (d) 1/8
32. 32.A bag has 8 white, 6 green and 2 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 5/8 (c) 3/5 (d) 3/8
33. 33.A bag has 5 blue, 2 red and 5 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 1/6 (c) 11/12 (d) 5/6
34. 34.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/3 (b) 1/4 (c) 2/3 (d) 5/6
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 1/9 (c) 1/11 (d) 4/11
36. 36.A bag has 2 white, 6 yellow and 2 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 9/10 (b) 1/3 (c) 4/5 (d) 1/5
37. 37.A bag has 7 green, 5 yellow and 9 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/7 (b) 1/3 (c) 13/21 (d) 4/7
38. 38.A bag has 4 red, 9 green and 8 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 3/4 (c) 3/7 (d) 4/7
39. 39.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/36 (c) 1/12 (d) 1/18
40. 40.A bag has 2 red, 9 green and 7 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/18 (b) 1/3 (c) 5/9 (d) 1/2

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