Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 186 · 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) 3/11 (b) 1/11 (c) 1/12 (d) 1/9
2. 2.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
3. 3.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
4. 4.A bag has 3 blue, 2 green and 9 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/6 (b) 1/7 (c) 6/7 (d) 1/3
5. 5.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
6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 1/11 (c) 1/9 (d) 4/11
7. 7.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 1/4 (c) 1/2 (d) 2/3
8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/11 (b) 6/11 (c) 7/36 (d) 1/6
9. 9.A bag has 2 yellow, 2 white and 4 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/2 (b) 1/8 (c) 1/3 (d) 5/8
10. 10.A bag has 2 green, 2 white and 7 blue balls. One ball is taken out without looking. What is the probability that it is not white? (a) 10/11 (b) 2/11 (c) 1/3 (d) 9/11
11. 11.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
12. 12.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
13. 13.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/3 (b) 3/4 (c) 1/4 (d) 1/2
14. 14.A bag has 4 green, 4 red and 9 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 13/17 (c) 14/17 (d) 4/17
15. 15.A bag has 3 red, 3 green and 3 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 1/2 (c) 2/3 (d) 4/9
16. 16.A bag has 4 green, 4 blue and 5 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 5/8 (b) 1/3 (c) 5/13 (d) 8/13
17. 17.A bag has 5 red, 2 green and 4 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 4/11 (b) 7/11 (c) 8/11 (d) 1/3
18. 18.A bag has 3 blue, 6 yellow and 2 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/9 (b) 2/11 (c) 1/3 (d) 9/11
19. 19.A bag has 2 yellow, 7 red and 9 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/9 (b) 1/3 (c) 8/9 (d) 1/8
20. 20.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) 2/3 (d) 1/3
21. 21.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
22. 22.A bag has 6 red, 3 green and 7 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 7/16 (c) 7/9 (d) 9/16
23. 23.A bag has 8 green, 3 blue and 5 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 7/8 (c) 13/16 (d) 3/16
24. 24.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/5 (b) 1/3 (c) 5/6 (d) 1/6
25. 25.A bag has 4 red, 3 blue and 2 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/3 (b) 1/2 (c) 4/9 (d) 1/3
26. 26.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/6
27. 27.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
28. 28.Three coins are tossed together. What is the probability of getting at least one head? (a) 7/8 (b) 1/8 (c) 1/4 (d) 3/8
29. 29.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
30. 30.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 1/6 (c) 5/36 (d) 1/11
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 2/11 (c) 1/18 (d) 1/12
32. 32.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
33. 33.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
34. 34.A bag has 4 blue, 7 green and 8 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/12 (b) 1/3 (c) 12/19 (d) 7/19
35. 35.A bag has 6 red, 5 blue and 9 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 1/4 (c) 4/5 (d) 3/4
36. 36.A bag has 8 red, 8 blue and 5 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 16/21 (c) 5/21 (d) 17/21
37. 37.A bag has 5 yellow, 2 red and 2 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 2/3 (c) 4/9 (d) 5/9
38. 38.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/12 (b) 1/36 (c) 1/18 (d) 1/11
39. 39.A bag has 8 white, 3 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/14 (b) 1/3 (c) 11/14 (d) 3/11
40. 40.A bag has 2 red, 6 blue and 7 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 3/5 (c) 2/3 (d) 2/5

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