Probability Worksheet for Class 8 Maths Olympiad

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

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