Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 661 · 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 multiple of 3? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 7/36 (b) 6/11 (c) 1/11 (d) 1/6
3. 3.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 1/3 (c) 2/3 (d) 1/4
4. 4.A bag has 8 yellow, 6 blue and 9 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 14/23 (b) 1/3 (c) 9/14 (d) 9/23
5. 5.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 1/2 (c) 2/3 (d) 1/3
6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/11 (b) 3/11 (c) 1/9 (d) 1/12
7. 7.A bag has 7 red, 9 blue and 3 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/19 (b) 1/3 (c) 3/16 (d) 16/19
8. 8.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/8 (b) 1/4 (c) 7/8 (d) 1/7
9. 9.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 2/11 (b) 1/11 (c) 1/18 (d) 1/12
10. 10.A bag has 8 white, 4 green and 8 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/5 (b) 1/3 (c) 3/5 (d) 2/3
11. 11.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/6 (b) 1/3 (c) 5/6 (d) 1/5
12. 12.A bag has 5 green, 9 white and 3 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 3/17 (b) 14/17 (c) 15/17 (d) 1/3
13. 13.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
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/18 (c) 1/12 (d) 1/36
15. 15.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/3 (b) 1/2 (c) 1/4 (d) 3/4
16. 16.A bag has 3 yellow, 3 red and 6 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/4 (b) 3/4 (c) 1/3 (d) 1/12
17. 17.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
18. 18.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/11 (b) 5/36 (c) 1/6 (d) 5/11
19. 19.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
20. 20.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
21. 21.A bag has 9 green, 3 red and 8 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 2/5 (b) 13/20 (c) 3/5 (d) 1/3
22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/9 (c) 1/11 (d) 1/12
23. 23.A bag has 6 blue, 7 white and 2 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 2/13 (c) 2/15 (d) 13/15
24. 24.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 7/8 (c) 3/8 (d) 1/8
25. 25.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/4 (b) 1/4 (c) 1/8 (d) 3/8
26. 26.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/4
27. 27.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
28. 28.A bag has 8 blue, 4 yellow and 4 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/4 (b) 1/4 (c) 1/3 (d) 5/16
29. 29.A bag has 3 blue, 3 red and 2 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 3/5 (c) 3/8 (d) 5/8
30. 30.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 2/3 (b) 1/4 (c) 1/3 (d) 1/2
31. 31.A bag has 8 blue, 6 red and 4 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 4/9 (c) 5/9 (d) 11/18
32. 32.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 3/5 (c) 1/4 (d) 5/8
33. 33.A bag has 9 blue, 8 green and 3 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 9/20 (b) 1/3 (c) 9/11 (d) 11/20
34. 34.A bag has 5 blue, 2 white and 8 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 7/15 (b) 8/15 (c) 3/5 (d) 1/3
35. 35.A bag has 7 red, 2 yellow and 6 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/5 (b) 1/3 (c) 2/3 (d) 3/5
36. 36.A bag has 8 blue, 6 yellow and 4 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 4/5 (b) 4/9 (c) 5/9 (d) 1/3
37. 37.A bag has 8 blue, 3 white and 2 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/11 (b) 1/3 (c) 11/13 (d) 2/13
38. 38.A bag has 7 blue, 8 yellow and 5 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 4/5 (c) 1/4 (d) 3/4
39. 39.A bag has 4 white, 6 red and 4 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 5/7 (b) 2/7 (c) 1/3 (d) 2/5
40. 40.A bag has 6 yellow, 8 white and 2 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/8 (b) 1/3 (c) 7/8 (d) 15/16

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