Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 163 · 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 prime number? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 6/11 (c) 1/11 (d) 7/36
3. 3.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
4. 4.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
5. 5.A bag has 2 blue, 9 white and 6 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/15 (b) 15/17 (c) 1/3 (d) 2/17
6. 6.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/4 (b) 2/3 (c) 5/6 (d) 1/3
7. 7.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (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 6? (a) 1/6 (b) 5/36 (c) 5/11 (d) 1/11
9. 9.A bag has 3 white, 9 blue and 6 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/5 (b) 1/6 (c) 1/3 (d) 5/6
10. 10.A bag has 8 blue, 7 red and 8 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 8/15 (b) 1/3 (c) 15/23 (d) 8/23
11. 11.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) 3/8 (d) 1/8
12. 12.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/8 (c) 1/7 (d) 1/4
13. 13.A bag has 7 yellow, 2 red and 6 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 2/3 (c) 2/5 (d) 3/5
14. 14.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/2 (c) 3/4 (d) 1/3
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/11 (b) 1/9 (c) 3/11 (d) 1/12
16. 16.A bag has 3 white, 4 yellow and 2 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 4/9 (b) 4/5 (c) 1/3 (d) 5/9
17. 17.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 yellow? (a) 3/5 (b) 5/8 (c) 3/8 (d) 1/3
18. 18.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 1/2 (c) 2/3 (d) 1/3
19. 19.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
20. 20.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
21. 21.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
22. 22.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 3/8 (c) 1/4 (d) 5/8
23. 23.Three coins are tossed together. What is the probability of getting at least one head? (a) 3/8 (b) 1/8 (c) 1/4 (d) 7/8
24. 24.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/11 (b) 1/9 (c) 5/36 (d) 4/11
26. 26.A bag has 8 red, 8 yellow and 3 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 8/19 (b) 1/3 (c) 12/19 (d) 11/19
27. 27.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
28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 5/36 (b) 4/11 (c) 1/9 (d) 1/11
29. 29.A bag has 9 white, 5 red and 8 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 17/22 (c) 5/17 (d) 5/22
30. 30.A bag has 9 green, 7 red and 2 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/9 (b) 1/2 (c) 1/18 (d) 1/3
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/11 (b) 1/6 (c) 5/36 (d) 1/11
32. 32.A bag has 2 blue, 4 yellow and 3 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 7/9 (b) 1/3 (c) 2/9 (d) 2/7
33. 33.A bag has 3 red, 4 blue and 9 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/8 (b) 1/3 (c) 9/16 (d) 7/16
34. 34.A bag has 2 yellow, 8 green and 3 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 2/13 (b) 1/3 (c) 12/13 (d) 11/13
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/18 (b) 1/11 (c) 2/11 (d) 1/12
36. 36.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 1/12 (c) 1/11 (d) 3/11
37. 37.A bag has 5 red, 5 white and 4 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/9 (b) 1/3 (c) 9/14 (d) 5/14
38. 38.A bag has 2 white, 5 green and 7 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 4/7 (b) 1/2 (c) 1/14 (d) 1/3
39. 39.A bag has 7 green, 8 yellow and 9 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 17/24 (c) 2/3 (d) 1/24
40. 40.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2

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