Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 158 · 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 5 white, 2 red and 5 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 2/3 (b) 7/12 (c) 5/12 (d) 1/3
2. 2.A bag has 3 blue, 3 red and 4 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 3/7 (c) 3/10 (d) 7/10
3. 3.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 5/8 (c) 3/8 (d) 3/5
4. 4.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/11 (b) 7/36 (c) 6/11 (d) 1/6
5. 5.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 green? (a) 8/17 (b) 1/3 (c) 9/17 (d) 8/9
6. 6.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/4 (b) 5/6 (c) 1/3 (d) 2/3
7. 7.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/3 (b) 1/2 (c) 1/4 (d) 3/4
8. 8.A bag has 4 red, 5 green and 2 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 4/11 (b) 1/3 (c) 7/11 (d) 4/7
9. 9.A bag has 3 blue, 6 red and 7 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 3/16 (b) 7/8 (c) 13/16 (d) 1/3
10. 10.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
11. 11.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/8 (b) 3/8 (c) 3/4 (d) 1/4
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/11 (b) 1/6 (c) 5/36 (d) 5/11
13. 13.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/11 (b) 1/6 (c) 1/11 (d) 5/36
14. 14.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 5/6 (b) 1/5 (c) 1/3 (d) 1/6
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/9 (c) 1/11 (d) 1/12
16. 16.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 5/6 (b) 1/6 (c) 1/3 (d) 1/5
17. 17.A bag has 9 yellow, 5 blue and 7 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/4 (b) 3/7 (c) 1/3 (d) 4/7
18. 18.A bag has 2 yellow, 9 red and 2 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 4/9 (b) 9/13 (c) 1/3 (d) 4/13
19. 19.Three coins are tossed together. What is the probability of getting at least one head? (a) 3/8 (b) 1/4 (c) 1/8 (d) 7/8
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 4/11 (b) 1/9 (c) 5/36 (d) 1/11
21. 21.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
22. 22.A bag has 7 green, 4 red and 3 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 3/14 (b) 1/3 (c) 11/14 (d) 6/7
23. 23.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 1/4 (c) 1/2 (d) 2/3
24. 24.A bag has 5 white, 2 yellow and 7 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 4/7 (c) 1/14 (d) 1/2
25. 25.A bag has 5 blue, 5 green and 8 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 4/9 (b) 1/3 (c) 5/9 (d) 11/18
26. 26.A bag has 8 white, 5 blue and 5 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 5/18 (b) 1/3 (c) 13/18 (d) 7/9
27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 1/11 (c) 1/12 (d) 3/11
28. 28.A bag has 2 yellow, 5 red and 6 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/13 (b) 1/3 (c) 5/8 (d) 8/13
29. 29.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
30. 30.A bag has 3 green, 9 yellow and 4 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 3/16 (b) 7/8 (c) 1/3 (d) 13/16
31. 31.A bag has 2 white, 4 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/7 (b) 7/9 (c) 2/9 (d) 1/3
32. 32.A bag has 4 white, 4 green and 5 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 9/13 (c) 4/13 (d) 10/13
33. 33.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 2/3 (b) 5/6 (c) 1/4 (d) 1/3
34. 34.A bag has 7 blue, 3 yellow and 9 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 7/12 (b) 1/3 (c) 12/19 (d) 7/19
35. 35.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/7 (c) 1/8 (d) 7/8
36. 36.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
37. 37.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
38. 38.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
39. 39.A bag has 7 blue, 4 red and 7 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 5/6 (c) 7/9 (d) 2/9
40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/18 (c) 1/12 (d) 1/36

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