Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 89 · 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 8? (a) 5/11 (b) 1/6 (c) 5/36 (d) 1/11
2. 2.Three coins are tossed together. What is the probability of getting at least one head? (a) 3/8 (b) 7/8 (c) 1/4 (d) 1/8
3. 3.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
4. 4.A bag has 2 green, 3 blue and 3 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 5/8 (b) 3/4 (c) 3/8 (d) 1/3
5. 5.A bag has 6 green, 6 blue and 8 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 3/10 (b) 7/10 (c) 3/4 (d) 1/3
6. 6.A bag has 8 white, 8 red and 2 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 11/18 (b) 1/3 (c) 4/9 (d) 5/9
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 2/11 (b) 1/12 (c) 1/11 (d) 1/18
8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/12 (b) 1/18 (c) 1/36 (d) 1/11
9. 9.A bag has 8 yellow, 5 white and 4 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 13/17 (b) 1/3 (c) 5/17 (d) 12/17
10. 10.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
11. 11.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/6
12. 12.A bag has 4 white, 5 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/4 (b) 1/12 (c) 1/3 (d) 3/4
13. 13.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 3/11 (c) 1/11 (d) 1/12
14. 14.A bag has 4 green, 4 red and 6 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 2/7 (b) 5/7 (c) 1/3 (d) 11/14
15. 15.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
16. 16.A bag has 4 red, 3 white and 4 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/8 (b) 3/11 (c) 8/11 (d) 1/3
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 4/11 (b) 5/36 (c) 1/11 (d) 1/9
18. 18.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 5/8 (c) 1/4 (d) 3/8
19. 19.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/12 (b) 1/11 (c) 1/36 (d) 1/18
20. 20.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) 1/4 (d) 3/8
21. 21.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
22. 22.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 1/3 (c) 1/2 (d) 2/3
23. 23.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/2 (b) 1/3 (c) 1/6 (d) 2/3
24. 24.A bag has 5 blue, 8 red and 6 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 11/19 (b) 1/3 (c) 12/19 (d) 8/19
25. 25.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/7 (b) 1/8 (c) 7/8 (d) 1/4
26. 26.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 3/4 (c) 1/3 (d) 1/4
27. 27.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 5/36 (c) 1/11 (d) 1/6
29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/11 (b) 4/11 (c) 5/36 (d) 1/9
30. 30.A bag has 9 white, 2 green and 3 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 5/7 (b) 5/14 (c) 9/14 (d) 1/3
31. 31.A bag has 7 green, 5 blue and 6 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 11/18 (b) 1/3 (c) 7/11 (d) 7/18
32. 32.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
33. 33.A bag has 4 green, 6 white and 3 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 8/13 (b) 7/13 (c) 6/13 (d) 1/3
34. 34.A bag has 4 white, 4 green and 3 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 4/11 (b) 7/11 (c) 4/7 (d) 1/3
35. 35.A bag has 8 white, 5 blue and 4 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 4/17 (b) 14/17 (c) 1/3 (d) 13/17
36. 36.A bag has 2 yellow, 7 red and 3 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 7/12 (b) 5/12 (c) 1/3 (d) 5/7
37. 37.A bag has 6 blue, 6 white and 2 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 4/7 (b) 1/3 (c) 3/4 (d) 3/7
38. 38.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/6 (b) 1/5 (c) 1/3 (d) 5/6
39. 39.A bag has 6 red, 4 white and 2 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 7/12 (b) 1/12 (c) 1/2 (d) 1/3
40. 40.A bag has 4 green, 5 white and 4 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 4/9 (b) 1/3 (c) 4/13 (d) 9/13

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