Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 148 · 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) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
2. 2.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 5/8 (c) 1/4 (d) 3/5
3. 3.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
4. 4.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/6 (b) 5/6 (c) 1/3 (d) 1/5
5. 5.A bag has 2 white, 9 red and 3 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 9/14 (c) 5/14 (d) 5/7
6. 6.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 1/4 (c) 1/3 (d) 2/3
7. 7.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 3/8 (c) 3/4 (d) 1/8
8. 8.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/4
9. 9.A bag has 6 red, 6 green and 4 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 5/8 (b) 11/16 (c) 1/3 (d) 3/8
10. 10.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/4 (c) 3/4 (d) 1/2
11. 11.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
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/36 (b) 5/11 (c) 1/11 (d) 1/6
13. 13.A bag has 9 red, 7 green and 6 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 9/22 (c) 7/11 (d) 13/22
14. 14.A bag has 9 white, 3 yellow and 9 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 6/7 (b) 19/21 (c) 1/7 (d) 1/3
15. 15.A bag has 2 blue, 7 white and 8 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 11/17 (b) 10/17 (c) 1/3 (d) 7/17
16. 16.A bag has 9 red, 2 blue and 7 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/9 (b) 8/9 (c) 1/3 (d) 17/18
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/9 (b) 4/11 (c) 1/11 (d) 5/36
18. 18.A bag has 3 yellow, 5 red and 8 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 1/2 (c) 9/16 (d) 1/16
19. 19.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/4 (c) 1/8 (d) 1/7
20. 20.A bag has 2 green, 5 red and 3 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 7/10 (b) 1/3 (c) 3/10 (d) 3/7
21. 21.A bag has 5 white, 2 red and 3 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/5 (b) 1/3 (c) 1/4 (d) 4/5
22. 22.A bag has 8 blue, 2 green and 3 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 10/13 (b) 1/3 (c) 3/10 (d) 3/13
23. 23.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/11 (b) 5/11 (c) 1/6 (d) 5/36
24. 24.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 5/6 (c) 2/3 (d) 1/4
25. 25.A bag has 7 yellow, 9 green and 4 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 7/20 (b) 7/10 (c) 13/20 (d) 1/3
26. 26.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 1/4 (c) 3/4 (d) 1/3
27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 4/11 (b) 1/9 (c) 1/11 (d) 5/36
28. 28.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 2/3 (c) 1/2 (d) 1/6
29. 29.A bag has 4 yellow, 3 blue and 2 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/9 (b) 7/9 (c) 1/3 (d) 2/3
30. 30.A bag has 4 green, 3 yellow and 5 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 1/4 (c) 1/12 (d) 3/4
31. 31.A bag has 5 blue, 8 green and 7 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 13/20 (b) 7/20 (c) 7/13 (d) 1/3
32. 32.A bag has 9 yellow, 8 white and 6 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 8/15 (c) 8/23 (d) 15/23
33. 33.A bag has 8 yellow, 8 red and 9 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 17/25 (c) 8/25 (d) 8/17
34. 34.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
35. 35.A bag has 3 red, 5 white and 7 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/5 (b) 4/5 (c) 1/4 (d) 1/3
36. 36.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/11 (b) 1/12 (c) 2/11 (d) 1/18
37. 37.A bag has 2 white, 3 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 3/8 (b) 3/4 (c) 5/8 (d) 1/3
38. 38.A bag has 4 blue, 3 yellow and 2 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 2/3 (c) 4/9 (d) 5/9
39. 39.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 2/3 (b) 1/3 (c) 5/6 (d) 1/4
40. 40.A bag has 6 yellow, 5 green and 4 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 4/15 (b) 1/3 (c) 11/15 (d) 4/5

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