Probability Worksheet for Class 8 Maths Olympiad

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

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