Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 184 · 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, 3 white and 2 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 3/14 (b) 6/7 (c) 1/3 (d) 11/14
2. 2.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/8 (b) 3/4 (c) 1/8 (d) 1/4
3. 3.A bag has 5 blue, 4 white and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 2/3 (c) 5/12 (d) 7/12
4. 4.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
5. 5.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 1/2 (c) 1/3 (d) 2/3
6. 6.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
7. 7.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
8. 8.A bag has 2 red, 8 green and 6 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 1/7 (c) 1/8 (d) 7/8
9. 9.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
10. 10.A bag has 7 blue, 4 white and 8 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 7/19 (c) 12/19 (d) 7/12
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/12 (c) 1/11 (d) 1/9
12. 12.A bag has 6 green, 9 yellow and 3 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/3 (b) 7/18 (c) 1/3 (d) 1/2
13. 13.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 1/2 (c) 2/3 (d) 1/3
14. 14.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 2/3 (c) 1/4 (d) 1/2
15. 15.A bag has 4 red, 4 green and 4 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/3 (b) 1/2 (c) 1/3 (d) 5/12
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 1/9 (c) 1/11 (d) 3/11
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/9 (b) 1/11 (c) 5/36 (d) 4/11
18. 18.A bag has 3 red, 2 yellow and 9 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 5/14 (b) 5/7 (c) 9/14 (d) 1/3
19. 19.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/12 (b) 1/18 (c) 1/11 (d) 1/36
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/11 (b) 1/11 (c) 1/6 (d) 5/36
21. 21.A bag has 7 green, 4 white and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 13/19 (b) 1/3 (c) 12/19 (d) 7/19
22. 22.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/8 (c) 5/8 (d) 3/5
23. 23.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 5/6 (c) 1/4 (d) 2/3
24. 24.A bag has 6 white, 2 blue and 5 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 8/13 (b) 9/13 (c) 5/13 (d) 1/3
25. 25.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 7/8 (c) 1/7 (d) 1/8
26. 26.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/18 (b) 1/11 (c) 1/12 (d) 1/36
27. 27.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
28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 1/12 (c) 1/18 (d) 2/11
29. 29.A bag has 9 yellow, 4 red and 5 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 7/9 (b) 13/18 (c) 1/3 (d) 5/18
30. 30.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/3 (b) 1/6 (c) 5/6 (d) 1/5
31. 31.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/6 (b) 1/3 (c) 1/5 (d) 5/6
32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/11 (b) 1/9 (c) 4/11 (d) 5/36
33. 33.A bag has 7 green, 4 blue and 7 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 2/3 (b) 1/3 (c) 11/18 (d) 7/18
34. 34.A bag has 2 blue, 4 green and 7 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 9/13 (b) 4/9 (c) 4/13 (d) 1/3
35. 35.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
36. 36.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
37. 37.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/18 (b) 2/11 (c) 1/11 (d) 1/12
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) 3/4 (d) 1/2
39. 39.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/3 (b) 1/4 (c) 5/6 (d) 2/3
40. 40.A bag has 4 blue, 9 green and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 4/17 (c) 13/17 (d) 14/17

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