Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 168 · 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 blue, 8 red and 6 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 1/7 (c) 1/8 (d) 7/8
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/36 (b) 1/6 (c) 1/11 (d) 5/11
3. 3.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
4. 4.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/11 (b) 4/11 (c) 5/36 (d) 1/9
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/11 (b) 1/12 (c) 3/11 (d) 1/9
6. 6.A bag has 2 yellow, 2 blue and 5 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 7/9 (b) 2/9 (c) 2/7 (d) 1/3
7. 7.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 1/4 (c) 3/8 (d) 7/8
8. 8.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 1/3 (c) 1/4 (d) 3/4
9. 9.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/12 (c) 1/36 (d) 1/18
10. 10.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 1/11 (c) 1/18 (d) 2/11
11. 11.A bag has 3 white, 6 green and 6 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 2/3 (b) 1/3 (c) 2/5 (d) 3/5
12. 12.A bag has 9 red, 2 white and 9 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 11/20 (b) 3/5 (c) 9/20 (d) 1/3
13. 13.A bag has 2 yellow, 4 white and 4 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/5 (b) 2/5 (c) 1/3 (d) 2/3
14. 14.Two coins are tossed together. What is the probability of getting exactly one head? (a) 2/3 (b) 1/4 (c) 1/3 (d) 1/2
15. 15.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/18 (b) 2/11 (c) 1/12 (d) 1/11
17. 17.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
18. 18.A bag has 3 red, 3 green and 2 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 3/8 (c) 5/8 (d) 3/4
19. 19.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/6 (b) 1/3 (c) 5/6 (d) 1/5
20. 20.A bag has 6 blue, 3 red and 2 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/8 (b) 1/3 (c) 8/11 (d) 3/11
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/36 (c) 1/12 (d) 1/18
22. 22.A bag has 2 red, 7 green and 3 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/12 (b) 2/3 (c) 5/12 (d) 1/3
23. 23.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
24. 24.A bag has 2 green, 4 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 6/7 (c) 13/14 (d) 1/7
25. 25.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/2 (c) 1/4 (d) 3/4
26. 26.A bag has 2 yellow, 4 green and 6 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 7/12 (b) 1/12 (c) 1/3 (d) 1/2
27. 27.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) 1/2 (d) 1/3
28. 28.A bag has 3 red, 2 blue and 4 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/7 (b) 1/3 (c) 7/9 (d) 2/9
29. 29.A bag has 8 green, 9 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 16/25 (c) 9/25 (d) 9/16
30. 30.A bag has 4 yellow, 4 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 4/7 (b) 7/11 (c) 4/11 (d) 1/3
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 7/36 (b) 1/11 (c) 1/6 (d) 6/11
32. 32.A bag has 3 white, 9 red and 5 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 8/17 (b) 9/17 (c) 8/9 (d) 1/3
33. 33.A bag has 2 blue, 2 red and 6 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/4 (b) 1/5 (c) 1/3 (d) 4/5
34. 34.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
35. 35.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) 3/4 (d) 1/8
36. 36.A bag has 3 red, 8 green and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 3/7 (b) 4/7 (c) 3/4 (d) 1/3
37. 37.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
38. 38.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 3/8 (c) 5/8 (d) 1/4
39. 39.A bag has 3 red, 8 yellow and 5 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 13/16 (b) 1/3 (c) 3/16 (d) 7/8
40. 40.A bag has 4 green, 8 red and 2 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 11/14 (c) 5/7 (d) 2/7

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