Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 133 · 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.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 7/8 (c) 1/4 (d) 3/8
2. 2.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/2 (b) 1/4 (c) 1/3 (d) 2/3
3. 3.A bag has 5 white, 8 red and 4 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 4/17 (b) 13/17 (c) 1/3 (d) 14/17
4. 4.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 2/11 (b) 1/18 (c) 1/11 (d) 1/12
5. 5.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 3/4 (c) 1/2 (d) 1/4
6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 2/11 (c) 1/12 (d) 1/18
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 5/36 (c) 1/6 (d) 1/11
8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/11 (c) 1/9 (d) 1/12
9. 9.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/11 (b) 5/36 (c) 5/11 (d) 1/6
10. 10.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/6 (b) 1/3 (c) 5/6 (d) 1/5
11. 11.A bag has 9 green, 5 blue and 4 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 2/9 (b) 5/6 (c) 7/9 (d) 1/3
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/12 (b) 1/18 (c) 1/11 (d) 1/36
13. 13.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 7/36 (c) 1/11 (d) 6/11
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/11 (b) 5/36 (c) 1/9 (d) 4/11
15. 15.A bag has 2 yellow, 5 white and 5 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 7/12 (b) 1/3 (c) 2/3 (d) 5/12
16. 16.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 2/3 (c) 1/3 (d) 1/2
17. 17.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/5 (c) 3/8 (d) 5/8
18. 18.A bag has 8 red, 7 yellow and 2 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 15/17 (b) 2/17 (c) 1/3 (d) 2/15
19. 19.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/18 (c) 1/36 (d) 1/12
21. 21.A bag has 5 blue, 5 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/13 (b) 1/3 (c) 5/18 (d) 13/18
22. 22.A bag has 3 red, 3 yellow and 5 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 5/6 (b) 1/3 (c) 6/11 (d) 5/11
23. 23.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/4 (c) 1/7 (d) 1/8
24. 24.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/2 (c) 3/4 (d) 1/3
25. 25.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 2/3 (c) 5/6 (d) 1/4
26. 26.A bag has 2 red, 4 green and 7 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/13 (b) 6/13 (c) 8/13 (d) 1/3
27. 27.A bag has 3 green, 2 red and 9 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 3/14 (b) 1/3 (c) 11/14 (d) 6/7
28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 4/11 (c) 1/11 (d) 1/9
29. 29.A bag has 7 green, 2 yellow and 3 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/5 (b) 1/3 (c) 5/6 (d) 1/6
30. 30.A bag has 9 white, 5 red and 6 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 3/7 (b) 1/3 (c) 3/10 (d) 7/10
31. 31.A bag has 7 yellow, 2 red and 6 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 13/15 (b) 1/3 (c) 2/15 (d) 2/13
32. 32.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
33. 33.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
34. 34.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 5/6 (b) 2/3 (c) 1/3 (d) 1/4
35. 35.A bag has 3 white, 7 red and 9 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 9/10 (b) 9/19 (c) 1/3 (d) 10/19
36. 36.A bag has 4 blue, 8 white and 7 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 15/19 (b) 1/3 (c) 4/19 (d) 4/15
37. 37.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
38. 38.A bag has 5 red, 8 blue and 6 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 13/19 (b) 6/13 (c) 6/19 (d) 1/3
39. 39.A bag has 3 green, 7 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) 1/4 (c) 5/6 (d) 3/4
40. 40.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2

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