Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 325 · 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 8? (a) 5/36 (b) 5/11 (c) 1/6 (d) 1/11
2. 2.A bag has 7 green, 2 red and 4 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 11/13 (b) 2/13 (c) 2/11 (d) 1/3
3. 3.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/5 (b) 1/3 (c) 1/6 (d) 5/6
4. 4.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
5. 5.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/11 (b) 1/12 (c) 3/11 (d) 1/9
7. 7.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 7/8 (c) 3/8 (d) 1/4
8. 8.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/4
9. 9.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
10. 10.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/3 (b) 1/6 (c) 1/5 (d) 5/6
11. 11.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/4 (b) 1/3 (c) 2/3 (d) 5/6
12. 12.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) 2/3 (d) 1/3
13. 13.A bag has 9 white, 4 green and 5 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 2/9 (c) 2/7 (d) 7/9
14. 14.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
15. 15.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
16. 16.A bag has 6 yellow, 7 white and 4 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 13/17 (b) 4/17 (c) 1/3 (d) 14/17
17. 17.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/7 (c) 1/8 (d) 7/8
18. 18.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) 1/8 (d) 1/4
19. 19.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
20. 20.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/11 (b) 6/11 (c) 1/6 (d) 7/36
22. 22.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
23. 23.A bag has 3 yellow, 6 green and 4 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 3/13 (b) 1/3 (c) 11/13 (d) 10/13
24. 24.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 1/3 (c) 5/6 (d) 1/4
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 1/18 (c) 1/12 (d) 2/11
26. 26.A bag has 6 green, 8 yellow and 6 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 3/7 (b) 1/3 (c) 7/10 (d) 3/10
27. 27.A bag has 4 green, 4 white and 3 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/11 (b) 4/7 (c) 4/11 (d) 1/3
28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/12 (c) 1/18 (d) 1/36
29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 1/11 (c) 5/36 (d) 1/6
30. 30.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/11 (b) 1/18 (c) 2/11 (d) 1/12
31. 31.A bag has 2 yellow, 5 red and 8 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 14/15 (c) 13/15 (d) 2/15
32. 32.A bag has 9 yellow, 5 white and 7 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 3/7 (c) 3/4 (d) 4/7
33. 33.A bag has 2 blue, 7 red and 2 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 2/11 (b) 1/3 (c) 2/9 (d) 9/11
34. 34.A bag has 5 green, 6 blue and 3 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/11 (b) 11/14 (c) 1/3 (d) 3/14
35. 35.A bag has 2 yellow, 2 green and 3 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 5/7 (b) 2/7 (c) 6/7 (d) 1/3
36. 36.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/4 (b) 5/6 (c) 2/3 (d) 1/3
37. 37.A bag has 4 red, 3 green and 7 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 5/7 (c) 11/14 (d) 2/7
38. 38.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/3 (c) 1/2 (d) 3/4
39. 39.A bag has 7 red, 8 yellow and 4 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 7/12 (b) 7/19 (c) 1/3 (d) 12/19
40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 4/11 (c) 1/9 (d) 1/11

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