Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 624 · 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.Three coins are tossed together. What is the probability of getting exactly one head? (a) 5/8 (b) 1/4 (c) 3/5 (d) 3/8
2. 2.A bag has 9 white, 4 green and 5 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/2 (b) 5/9 (c) 1/3 (d) 1/18
3. 3.A bag has 9 green, 3 white and 9 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 4/7 (b) 3/4 (c) 1/3 (d) 3/7
4. 4.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/11 (c) 1/36 (d) 1/12
6. 6.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 5/6 (c) 1/3 (d) 1/4
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 1/9 (c) 3/11 (d) 1/11
8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/36 (b) 1/6 (c) 5/11 (d) 1/11
9. 9.A bag has 9 red, 9 yellow and 4 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 7/11 (b) 13/22 (c) 9/22 (d) 1/3
10. 10.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
11. 11.A bag has 9 green, 4 red and 6 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 15/19 (b) 4/19 (c) 16/19 (d) 1/3
12. 12.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/4 (b) 1/8 (c) 3/8 (d) 1/4
13. 13.A bag has 5 yellow, 6 white and 3 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 9/14 (b) 1/3 (c) 5/14 (d) 5/9
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/18 (b) 1/11 (c) 1/12 (d) 2/11
15. 15.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 2/3 (c) 1/2 (d) 1/3
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/11 (b) 1/6 (c) 6/11 (d) 7/36
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 1/11 (c) 2/11 (d) 1/18
18. 18.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/3 (b) 1/6 (c) 1/5 (d) 5/6
19. 19.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/3 (c) 3/4 (d) 1/2
20. 20.A bag has 2 red, 7 white and 2 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 2/11 (b) 2/9 (c) 1/3 (d) 9/11
21. 21.A bag has 4 green, 7 yellow and 8 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 16/19 (c) 4/19 (d) 15/19
22. 22.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
23. 23.A bag has 9 blue, 2 yellow and 7 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/18 (b) 1/3 (c) 5/9 (d) 1/2
24. 24.A bag has 2 red, 3 blue and 2 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/7 (b) 2/7 (c) 1/3 (d) 2/5
25. 25.A bag has 6 green, 7 red and 7 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 3/4 (b) 7/10 (c) 3/10 (d) 1/3
26. 26.A bag has 3 green, 4 white and 7 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 2/7 (b) 5/7 (c) 11/14 (d) 1/3
27. 27.A bag has 6 yellow, 6 red and 2 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 6/7 (b) 1/7 (c) 1/3 (d) 13/14
28. 28.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/6 (b) 5/36 (c) 1/11 (d) 5/11
30. 30.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/12 (b) 3/11 (c) 1/9 (d) 1/11
32. 32.A bag has 7 white, 3 yellow and 7 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 10/17 (b) 1/3 (c) 7/17 (d) 7/10
33. 33.A bag has 7 white, 7 green and 6 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 3/4 (c) 3/10 (d) 7/10
34. 34.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/5 (b) 1/3 (c) 1/6 (d) 5/6
35. 35.A bag has 8 red, 8 white and 3 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 11/19 (b) 12/19 (c) 1/3 (d) 8/19
36. 36.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/9 (b) 4/11 (c) 5/36 (d) 1/11
37. 37.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/11 (b) 4/11 (c) 5/36 (d) 1/9
38. 38.A bag has 3 white, 6 green and 6 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/3 (b) 3/5 (c) 2/5 (d) 1/3
39. 39.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/4 (b) 1/3 (c) 5/6 (d) 2/3
40. 40.A bag has 5 yellow, 8 red and 5 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 5/18 (c) 5/13 (d) 13/18

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