Probability Worksheet for Class 8 Maths Olympiad

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

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