Probability Worksheet for Class 8 Maths Olympiad

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

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