Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 894 · 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 fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
2. 2.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 1/6 (c) 2/3 (d) 1/3
3. 3.A bag has 9 blue, 3 green and 7 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 3/19 (b) 16/19 (c) 3/16 (d) 1/3
4. 4.A bag has 8 green, 6 red and 8 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 8/11 (b) 3/11 (c) 1/3 (d) 3/8
5. 5.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
6. 6.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
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/18 (b) 2/11 (c) 1/11 (d) 1/12
8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 1/11 (c) 6/11 (d) 7/36
9. 9.A bag has 8 yellow, 3 green and 9 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 17/20 (c) 3/20 (d) 3/17
10. 10.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
11. 11.A bag has 7 yellow, 2 white and 5 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 9/14 (b) 5/14 (c) 5/7 (d) 1/3
12. 12.A bag has 4 yellow, 3 white and 4 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 4/7 (b) 4/11 (c) 1/3 (d) 7/11
13. 13.A bag has 4 blue, 6 yellow and 7 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/10 (b) 10/17 (c) 7/17 (d) 1/3
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 5/36 (b) 1/9 (c) 1/11 (d) 4/11
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/12 (b) 1/18 (c) 1/36 (d) 1/11
16. 16.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
17. 17.A bag has 8 white, 7 blue and 2 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 15/17 (b) 1/3 (c) 2/15 (d) 2/17
18. 18.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 2/3 (c) 1/2 (d) 1/4
19. 19.A bag has 3 red, 9 blue and 2 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 5/14 (b) 5/9 (c) 1/3 (d) 9/14
20. 20.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 7/8 (c) 1/8 (d) 1/7
21. 21.A bag has 7 yellow, 6 red and 8 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 1/2 (c) 2/3 (d) 8/21
22. 22.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
23. 23.A bag has 8 green, 8 yellow and 8 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/24 (b) 2/3 (c) 17/24 (d) 1/3
24. 24.A bag has 7 green, 9 yellow and 3 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 9/10 (b) 10/19 (c) 1/3 (d) 9/19
25. 25.A bag has 6 yellow, 4 red and 4 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 11/14 (c) 2/7 (d) 5/7
26. 26.A bag has 2 red, 9 white and 9 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/10 (b) 9/10 (c) 1/3 (d) 1/9
27. 27.A bag has 5 white, 4 red and 5 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 5/14 (c) 5/9 (d) 9/14
28. 28.A bag has 2 red, 7 green and 3 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/12 (b) 2/3 (c) 7/12 (d) 1/3
29. 29.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/2 (c) 3/4 (d) 1/4
30. 30.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) 1/4 (d) 1/8
31. 31.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
32. 32.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 7/8 (c) 1/8 (d) 3/8
33. 33.A bag has 9 red, 3 blue and 9 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 13/21 (b) 1/3 (c) 4/7 (d) 3/7
34. 34.A bag has 3 blue, 6 red and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 1/4 (c) 3/4 (d) 5/6
35. 35.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 2/3 (c) 1/4 (d) 5/6
36. 36.A bag has 2 white, 6 red and 6 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 4/7 (b) 3/4 (c) 1/3 (d) 3/7
37. 37.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/3 (b) 2/3 (c) 1/2 (d) 1/6
38. 38.A bag has 4 blue, 3 green and 8 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/4 (b) 1/3 (c) 1/5 (d) 4/5
39. 39.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
40. 40.A bag has 9 blue, 6 red and 2 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 16/17 (c) 2/17 (d) 15/17

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