Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 274 · 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 fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/3 (b) 5/6 (c) 1/5 (d) 1/6
2. 2.A bag has 7 red, 2 white and 7 blue balls. One ball is taken out without looking. What is the probability that it is not white? (a) 15/16 (b) 7/8 (c) 1/3 (d) 1/8
3. 3.A bag has 3 blue, 4 yellow and 8 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/5 (b) 8/15 (c) 7/15 (d) 1/3
4. 4.Two coins are tossed together. What is the probability of getting at least one head? (a) 3/4 (b) 1/4 (c) 1/2 (d) 1/3
5. 5.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
6. 6.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
7. 7.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/5 (c) 5/8 (d) 3/8
8. 8.A bag has 3 blue, 2 yellow and 3 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/8 (b) 3/5 (c) 1/3 (d) 3/8
9. 9.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/11 (b) 4/11 (c) 5/36 (d) 1/9
10. 10.A bag has 2 green, 3 yellow and 2 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 4/7 (c) 3/7 (d) 3/4
11. 11.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/2 (b) 1/3 (c) 1/6 (d) 2/3
12. 12.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
13. 13.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 1/3 (c) 1/6 (d) 2/3
14. 14.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/2 (b) 1/6 (c) 2/3 (d) 1/3
15. 15.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/8 (c) 3/8 (d) 7/8
16. 16.A bag has 7 green, 6 white and 6 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 6/19 (b) 6/13 (c) 13/19 (d) 1/3
17. 17.A bag has 3 yellow, 2 green and 3 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 5/8 (b) 3/8 (c) 1/3 (d) 3/4
18. 18.A bag has 5 green, 3 blue and 7 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/5 (b) 1/4 (c) 1/3 (d) 4/5
19. 19.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 2/11 (c) 1/11 (d) 1/18
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/36 (b) 1/6 (c) 1/11 (d) 5/11
21. 21.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/2 (b) 3/4 (c) 1/3 (d) 1/4
22. 22.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
23. 23.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
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/36 (b) 1/12 (c) 1/11 (d) 1/18
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 1/11 (c) 1/9 (d) 3/11
26. 26.A bag has 7 green, 2 red and 4 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 6/13 (b) 8/13 (c) 1/3 (d) 7/13
27. 27.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
28. 28.A bag has 3 red, 8 blue and 5 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/13 (b) 3/16 (c) 13/16 (d) 1/3
29. 29.A bag has 2 red, 7 white and 8 blue balls. One ball is taken out without looking. What is the probability that it is not white? (a) 10/17 (b) 7/17 (c) 11/17 (d) 1/3
30. 30.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
31. 31.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
32. 32.Two coins are tossed together. What is the probability of getting exactly one head? (a) 2/3 (b) 1/3 (c) 1/4 (d) 1/2
33. 33.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/11 (c) 1/9 (d) 1/12
34. 34.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 white? (a) 3/16 (b) 1/3 (c) 3/13 (d) 13/16
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/11 (b) 5/11 (c) 1/6 (d) 5/36
36. 36.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/36 (b) 1/18 (c) 1/12 (d) 1/11
37. 37.A bag has 4 blue, 9 yellow and 5 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 5/18 (b) 1/3 (c) 13/18 (d) 5/13
38. 38.A bag has 5 green, 6 blue and 4 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/15 (b) 11/15 (c) 2/3 (d) 1/3
39. 39.A bag has 2 yellow, 6 blue and 5 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 8/13 (b) 5/8 (c) 1/3 (d) 5/13
40. 40.A bag has 8 white, 2 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/10 (b) 1/3 (c) 3/13 (d) 10/13

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