Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 66 · 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.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
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/9 (b) 3/11 (c) 1/11 (d) 1/12
3. 3.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
4. 4.A bag has 7 white, 7 yellow and 6 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 7/10 (c) 13/20 (d) 7/20
5. 5.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) 1/3 (d) 1/4
6. 6.A bag has 6 red, 4 yellow and 5 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/3 (b) 2/5 (c) 1/2 (d) 1/3
7. 7.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
8. 8.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 3/8 (c) 1/8 (d) 7/8
9. 9.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
10. 10.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 5/8 (c) 3/8 (d) 1/4
11. 11.A bag has 7 green, 7 yellow and 9 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/16 (b) 7/23 (c) 1/3 (d) 16/23
12. 12.A bag has 7 red, 8 blue and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 17/23 (b) 7/23 (c) 16/23 (d) 1/3
13. 13.A bag has 6 red, 9 green and 2 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 2/17 (b) 16/17 (c) 1/3 (d) 15/17
14. 14.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
15. 15.A bag has 7 red, 9 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 3/19 (c) 16/19 (d) 17/19
16. 16.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 1/2 (c) 1/4 (d) 2/3
17. 17.A bag has 8 green, 2 yellow and 3 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/10 (b) 10/13 (c) 1/3 (d) 3/13
18. 18.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
19. 19.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
20. 20.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 5/6 (b) 1/6 (c) 1/5 (d) 1/3
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/11 (b) 1/18 (c) 1/12 (d) 2/11
22. 22.A bag has 2 red, 5 white and 7 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/7 (b) 1/6 (c) 6/7 (d) 1/3
23. 23.A bag has 9 red, 7 white and 3 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 11/19 (c) 10/19 (d) 9/19
24. 24.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 1/4 (c) 1/3 (d) 2/3
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/36 (b) 1/11 (c) 5/11 (d) 1/6
26. 26.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/12 (b) 2/11 (c) 1/11 (d) 1/18
27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 5/36 (b) 1/11 (c) 1/9 (d) 4/11
28. 28.A bag has 4 yellow, 6 white and 4 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/7 (b) 1/3 (c) 5/7 (d) 2/5
29. 29.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/8 (b) 3/4 (c) 1/8 (d) 1/4
30. 30.A bag has 5 red, 5 white and 2 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 5/12 (c) 5/7 (d) 7/12
31. 31.A bag has 5 red, 3 blue and 7 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/5 (b) 13/15 (c) 4/5 (d) 1/3
32. 32.A bag has 3 red, 9 green and 6 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 8/9 (b) 5/6 (c) 1/3 (d) 1/6
33. 33.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
34. 34.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/4 (c) 1/2 (d) 3/4
35. 35.A bag has 6 green, 3 blue and 2 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 6/11 (b) 1/3 (c) 5/11 (d) 7/11
36. 36.Two coins are tossed together. What is the probability of getting at least one head? (a) 3/4 (b) 1/3 (c) 1/4 (d) 1/2
37. 37.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
38. 38.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
39. 39.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 not red? (a) 7/19 (b) 13/19 (c) 12/19 (d) 1/3
40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 3/11 (b) 1/11 (c) 1/12 (d) 1/9

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