Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 896 · 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) 1/6 (c) 2/3 (d) 1/2
2. 2.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
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 1/9 (c) 4/11 (d) 1/11
4. 4.A bag has 2 green, 8 blue and 2 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/6 (b) 1/5 (c) 1/3 (d) 1/6
5. 5.Three coins are tossed together. What is the probability of getting exactly one head? (a) 5/8 (b) 3/8 (c) 1/4 (d) 3/5
6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 2/11 (c) 1/18 (d) 1/11
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 dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/11 (b) 5/36 (c) 4/11 (d) 1/9
9. 9.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
10. 10.A bag has 3 green, 4 white and 4 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 4/7 (b) 4/11 (c) 7/11 (d) 1/3
11. 11.A bag has 7 green, 3 red and 7 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 7/10 (c) 10/17 (d) 7/17
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 1/12 (c) 2/11 (d) 1/18
13. 13.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/2 (b) 1/3 (c) 1/6 (d) 2/3
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 5/36 (c) 1/11 (d) 1/6
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/12 (b) 1/11 (c) 1/18 (d) 1/36
16. 16.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/4 (b) 2/3 (c) 1/3 (d) 5/6
17. 17.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
18. 18.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/3 (b) 2/3 (c) 1/4 (d) 1/2
19. 19.A bag has 2 blue, 6 green and 6 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 3/7 (b) 1/3 (c) 3/4 (d) 4/7
20. 20.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/8 (c) 7/8 (d) 1/7
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/12 (c) 1/18 (d) 1/36
22. 22.A bag has 4 white, 9 blue and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 3/16 (b) 7/8 (c) 13/16 (d) 1/3
23. 23.A bag has 8 yellow, 4 white and 2 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 13/14 (b) 6/7 (c) 1/3 (d) 1/7
24. 24.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
25. 25.A bag has 6 green, 9 white and 3 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/6 (b) 8/9 (c) 5/6 (d) 1/3
26. 26.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/11 (b) 6/11 (c) 1/6 (d) 7/36
27. 27.A bag has 4 blue, 2 white and 9 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/3 (b) 3/5 (c) 1/3 (d) 2/5
28. 28.A bag has 6 yellow, 8 red and 5 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 13/19 (b) 14/19 (c) 6/19 (d) 1/3
29. 29.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/3 (b) 2/3 (c) 1/4 (d) 5/6
30. 30.A bag has 7 white, 6 green and 6 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 6/19 (c) 14/19 (d) 13/19
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/9 (b) 1/12 (c) 3/11 (d) 1/11
32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 3/11 (b) 1/12 (c) 1/11 (d) 1/9
33. 33.A bag has 3 red, 7 white and 5 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/4 (b) 1/5 (c) 1/3 (d) 4/5
34. 34.A bag has 4 green, 5 red and 5 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/5 (b) 1/3 (c) 2/7 (d) 5/7
35. 35.A bag has 2 red, 9 green and 9 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/9 (b) 1/10 (c) 1/3 (d) 9/10
36. 36.A bag has 4 yellow, 9 white and 8 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 8/21 (c) 8/13 (d) 13/21
37. 37.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
38. 38.A bag has 4 yellow, 4 blue and 8 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 1/4 (c) 3/4 (d) 5/16
39. 39.A bag has 3 green, 4 yellow and 3 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 4/5 (c) 7/10 (d) 3/10
40. 40.A bag has 2 white, 3 yellow and 5 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/5 (b) 1/3 (c) 4/5 (d) 9/10

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