Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 344 · 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.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 2/3 (c) 1/4 (d) 1/2
2. 2.A bag has 9 blue, 3 red and 6 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 2/3 (b) 1/3 (c) 1/18 (d) 13/18
3. 3.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
4. 4.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
5. 5.A bag has 3 blue, 7 green and 3 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/13 (b) 1/3 (c) 3/10 (d) 10/13
6. 6.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
7. 7.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/4 (b) 3/8 (c) 1/4 (d) 1/8
8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 2/11 (b) 1/12 (c) 1/11 (d) 1/18
9. 9.A bag has 9 blue, 5 red and 3 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 8/17 (b) 1/3 (c) 8/9 (d) 9/17
10. 10.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/9 (b) 5/36 (c) 4/11 (d) 1/11
11. 11.A bag has 9 white, 6 red and 7 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 13/22 (b) 9/22 (c) 1/3 (d) 9/13
12. 12.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 1/4 (c) 1/3 (d) 2/3
13. 13.A bag has 8 yellow, 8 blue and 8 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 17/24 (c) 1/24 (d) 2/3
14. 14.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
15. 15.A bag has 2 yellow, 4 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/3 (b) 1/2 (c) 4/9 (d) 1/3
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/18 (b) 1/36 (c) 1/12 (d) 1/11
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 3/11 (b) 1/9 (c) 1/11 (d) 1/12
18. 18.A bag has 3 white, 9 yellow and 6 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 8/9 (b) 1/6 (c) 5/6 (d) 1/3
19. 19.A bag has 8 yellow, 3 blue and 8 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 16/19 (b) 17/19 (c) 1/3 (d) 3/19
20. 20.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/2 (b) 1/6 (c) 1/3 (d) 2/3
21. 21.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
22. 22.A bag has 3 yellow, 4 white and 2 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/7 (b) 2/9 (c) 7/9 (d) 1/3
23. 23.A bag has 8 blue, 2 green and 5 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 3/5 (c) 8/15 (d) 7/15
24. 24.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/2 (b) 1/3 (c) 1/4 (d) 3/4
25. 25.A bag has 4 yellow, 9 green and 2 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 13/15 (b) 2/13 (c) 2/15 (d) 1/3
26. 26.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/5 (c) 3/8 (d) 5/8
27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/12 (c) 1/11 (d) 1/36
28. 28.A bag has 3 white, 2 green and 2 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 5/7 (c) 6/7 (d) 2/7
29. 29.A bag has 7 white, 2 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/17 (b) 1/3 (c) 15/17 (d) 2/15
30. 30.A bag has 9 red, 8 green and 8 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 9/25 (b) 1/3 (c) 9/16 (d) 16/25
31. 31.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 5/6 (b) 1/3 (c) 2/3 (d) 1/4
32. 32.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/3 (c) 1/2 (d) 3/4
33. 33.A bag has 6 yellow, 4 green and 8 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/9 (b) 2/9 (c) 1/3 (d) 2/7
34. 34.A bag has 5 blue, 6 white and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 11/16 (c) 3/4 (d) 5/16
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/6 (b) 1/11 (c) 5/11 (d) 5/36
36. 36.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/7 (b) 1/8 (c) 7/8 (d) 1/4
37. 37.A bag has 8 blue, 2 red and 2 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/6 (b) 5/6 (c) 11/12 (d) 1/3
38. 38.A bag has 4 red, 9 green and 8 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 8/21 (c) 13/21 (d) 8/13
39. 39.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/9 (b) 5/36 (c) 1/11 (d) 4/11
40. 40.A bag has 2 blue, 7 yellow and 3 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/12 (b) 1/4 (c) 3/4 (d) 1/3

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