Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 479 · 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 3? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
2. 2.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
3. 3.A bag has 2 blue, 8 green and 5 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/2 (b) 1/3 (c) 2/3 (d) 2/5
4. 4.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/8 (b) 3/4 (c) 3/8 (d) 1/4
5. 5.A bag has 7 red, 4 green and 9 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 7/13 (b) 13/20 (c) 1/3 (d) 7/20
6. 6.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
7. 7.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 1/3 (c) 1/4 (d) 2/3
8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/11 (c) 1/36 (d) 1/12
9. 9.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 5/6 (b) 1/4 (c) 2/3 (d) 1/3
10. 10.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/3 (b) 1/4 (c) 1/2 (d) 2/3
11. 11.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 5/6 (c) 2/3 (d) 1/4
12. 12.A bag has 3 yellow, 9 blue and 7 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 10/19 (b) 9/19 (c) 1/3 (d) 9/10
13. 13.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
14. 14.A bag has 8 green, 7 white and 2 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 10/17 (b) 1/3 (c) 7/17 (d) 11/17
15. 15.A bag has 4 green, 7 yellow and 8 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 16/19 (b) 4/19 (c) 15/19 (d) 1/3
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 2/11 (b) 1/18 (c) 1/12 (d) 1/11
17. 17.A bag has 7 green, 6 yellow and 4 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/10 (b) 10/17 (c) 7/17 (d) 1/3
18. 18.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
19. 19.A bag has 3 red, 2 white and 2 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 2/7 (c) 5/7 (d) 2/5
20. 20.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
21. 21.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/2 (c) 1/4 (d) 3/4
22. 22.A bag has 2 red, 4 green and 7 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/13 (b) 1/3 (c) 2/11 (d) 11/13
23. 23.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 6/11 (b) 7/36 (c) 1/11 (d) 1/6
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/12 (b) 1/36 (c) 1/18 (d) 1/11
25. 25.A bag has 3 blue, 2 white and 6 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 9/11 (b) 2/9 (c) 2/11 (d) 1/3
26. 26.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 1/4 (c) 3/5 (d) 5/8
27. 27.A bag has 7 green, 5 yellow and 5 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 12/17 (c) 5/12 (d) 5/17
28. 28.A bag has 2 red, 4 blue and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 2/3 (b) 1/3 (c) 5/9 (d) 4/9
29. 29.A bag has 2 blue, 8 red and 2 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 5/12 (b) 1/2 (c) 2/3 (d) 1/3
30. 30.A bag has 2 blue, 4 red and 3 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/9 (b) 1/3 (c) 7/9 (d) 2/3
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/18 (b) 2/11 (c) 1/11 (d) 1/12
32. 32.A bag has 4 blue, 2 red and 8 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 6/7 (c) 1/7 (d) 13/14
33. 33.A bag has 8 blue, 2 yellow and 6 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 7/8 (c) 1/8 (d) 1/7
34. 34.A bag has 7 yellow, 3 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/19 (b) 12/19 (c) 7/12 (d) 1/3
35. 35.A bag has 3 green, 9 blue and 3 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 4/5 (b) 13/15 (c) 1/5 (d) 1/3
36. 36.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/4 (b) 1/3 (c) 5/6 (d) 2/3
37. 37.A bag has 7 yellow, 2 red and 4 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/11 (b) 2/13 (c) 1/3 (d) 11/13
38. 38.A bag has 9 yellow, 2 green and 6 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 16/17 (c) 2/17 (d) 15/17
39. 39.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/9 (b) 4/11 (c) 5/36 (d) 1/11
40. 40.A bag has 5 yellow, 3 green and 5 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 3/13 (b) 1/3 (c) 11/13 (d) 10/13

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