Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 320 · 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 at least one head and at least one tail? (a) 1/2 (b) 1/4 (c) 2/3 (d) 1/3
2. 2.A bag has 3 white, 4 green and 4 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 7/11 (c) 4/7 (d) 4/11
3. 3.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
4. 4.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 3/8 (c) 5/8 (d) 1/4
5. 5.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 3/8 (c) 7/8 (d) 1/4
6. 6.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
7. 7.A bag has 5 green, 2 white and 7 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 9/14 (b) 5/7 (c) 1/3 (d) 5/14
8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/6 (b) 5/36 (c) 5/11 (d) 1/11
9. 9.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/5 (b) 1/3 (c) 1/6 (d) 5/6
10. 10.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 1/18 (c) 2/11 (d) 1/11
11. 11.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 3/4 (b) 1/4 (c) 1/3 (d) 1/2
12. 12.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/3 (b) 3/4 (c) 1/2 (d) 1/4
13. 13.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 5/6 (c) 1/4 (d) 1/3
14. 14.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
15. 15.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 2/3 (c) 1/2 (d) 1/3
16. 16.A bag has 2 blue, 2 red and 2 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 6/11 (c) 7/36 (d) 1/11
18. 18.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 2/3 (c) 1/2 (d) 1/6
19. 19.A bag has 5 white, 6 red and 6 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 12/17 (b) 5/12 (c) 1/3 (d) 5/17
20. 20.A bag has 7 white, 3 blue and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 7/18 (c) 11/18 (d) 2/3
21. 21.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 red? (a) 3/7 (b) 7/10 (c) 3/10 (d) 1/3
22. 22.A bag has 2 red, 5 green and 3 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 9/10 (b) 1/5 (c) 1/3 (d) 4/5
23. 23.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
24. 24.A bag has 3 white, 5 green and 8 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/2 (b) 1/16 (c) 9/16 (d) 1/3
25. 25.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 5/6 (b) 2/3 (c) 1/4 (d) 1/3
26. 26.A bag has 8 red, 9 white and 3 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 9/20 (b) 11/20 (c) 1/3 (d) 3/5
27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/36 (b) 1/18 (c) 1/12 (d) 1/11
28. 28.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
29. 29.A bag has 7 blue, 4 red and 2 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 6/13 (b) 1/3 (c) 7/13 (d) 8/13
30. 30.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/12 (b) 2/11 (c) 1/11 (d) 1/18
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/12 (b) 1/11 (c) 3/11 (d) 1/9
32. 32.A bag has 2 white, 7 green and 6 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 2/3 (c) 3/5 (d) 2/5
33. 33.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
34. 34.A bag has 3 green, 5 blue and 6 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 3/11 (b) 1/3 (c) 3/14 (d) 11/14
35. 35.A bag has 7 blue, 3 green and 7 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 14/17 (b) 3/17 (c) 15/17 (d) 1/3
36. 36.A bag has 2 yellow, 3 white and 3 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/8 (b) 3/5 (c) 5/8 (d) 1/3
37. 37.A bag has 5 blue, 3 white and 3 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 6/11 (c) 5/11 (d) 5/6
38. 38.A bag has 6 yellow, 7 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 5/8 (c) 9/16 (d) 7/16
39. 39.A bag has 2 green, 9 blue and 3 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 6/7 (b) 1/6 (c) 1/3 (d) 1/7
40. 40.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/3 (b) 2/3 (c) 5/6 (d) 1/4

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