Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 169 · 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 bag has 9 green, 6 red and 9 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/4 (b) 19/24 (c) 1/3 (d) 1/4
2. 2.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
3. 3.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
4. 4.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/4
5. 5.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
6. 6.A bag has 8 white, 2 blue and 2 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 2/3 (b) 1/2 (c) 5/12 (d) 1/3
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 1/11 (c) 4/11 (d) 1/9
8. 8.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 5/6 (b) 1/4 (c) 2/3 (d) 1/3
9. 9.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
10. 10.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 7/8 (c) 3/8 (d) 1/4
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/11 (b) 3/11 (c) 1/12 (d) 1/9
12. 12.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 2/3 (c) 1/4 (d) 1/3
13. 13.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 3/5 (c) 1/4 (d) 5/8
14. 14.A bag has 2 white, 5 red and 4 blue balls. One ball is taken out without looking. What is the probability that it is not white? (a) 9/11 (b) 2/11 (c) 10/11 (d) 1/3
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 6/11 (b) 1/6 (c) 7/36 (d) 1/11
16. 16.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
17. 17.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/6
18. 18.A bag has 2 green, 6 yellow and 7 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 7/8 (b) 7/15 (c) 1/3 (d) 8/15
19. 19.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 5/6 (c) 1/4 (d) 2/3
20. 20.A bag has 5 green, 7 blue and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/15 (b) 2/3 (c) 1/3 (d) 11/15
21. 21.A bag has 3 blue, 3 red and 7 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 11/13 (b) 3/13 (c) 1/3 (d) 10/13
22. 22.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 3/4 (c) 1/2 (d) 1/4
23. 23.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
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 2/11 (b) 1/18 (c) 1/11 (d) 1/12
25. 25.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 1/8 (c) 3/4 (d) 3/8
26. 26.A bag has 6 green, 4 white and 2 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/2 (b) 7/12 (c) 1/3 (d) 1/12
27. 27.A bag has 4 blue, 3 red and 7 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/5 (b) 5/7 (c) 2/7 (d) 1/3
28. 28.A bag has 3 blue, 9 green and 6 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 1/5 (c) 1/6 (d) 5/6
29. 29.A bag has 3 white, 2 green and 6 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 5/11 (b) 6/11 (c) 5/6 (d) 1/3
30. 30.A bag has 5 white, 5 green and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 13/18 (b) 5/18 (c) 1/3 (d) 7/9
31. 31.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
32. 32.A bag has 2 yellow, 5 white and 8 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 7/15 (b) 7/8 (c) 1/3 (d) 8/15
33. 33.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
34. 34.A bag has 8 red, 3 green and 8 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 3/19 (b) 16/19 (c) 1/3 (d) 3/16
35. 35.A bag has 2 blue, 4 red and 8 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 4/7 (b) 1/3 (c) 3/7 (d) 9/14
36. 36.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
37. 37.A bag has 3 red, 4 white and 9 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 7/9 (b) 1/3 (c) 9/16 (d) 7/16
38. 38.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
39. 39.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 5/6 (b) 1/4 (c) 2/3 (d) 1/3
40. 40.A bag has 4 green, 9 yellow and 3 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 5/8 (c) 9/16 (d) 7/16

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