Probability Worksheet for Class 8 Maths Olympiad

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

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