Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 698 · 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 number less than 5? (a) 1/3 (b) 2/3 (c) 5/6 (d) 1/4
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/11 (b) 5/11 (c) 1/6 (d) 5/36
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/12 (b) 1/11 (c) 1/18 (d) 1/36
4. 4.A bag has 7 red, 8 green and 3 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 5/6 (b) 1/3 (c) 1/6 (d) 8/9
5. 5.A bag has 5 green, 9 white and 7 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/4 (b) 4/7 (c) 1/3 (d) 3/7
6. 6.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
7. 7.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
8. 8.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) 1/8 (d) 3/8
9. 9.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/2 (c) 1/3 (d) 3/4
10. 10.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/11 (b) 1/12 (c) 2/11 (d) 1/18
12. 12.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
13. 13.A bag has 7 green, 5 yellow and 2 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 5/14 (b) 9/14 (c) 5/7 (d) 1/3
14. 14.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 1/4 (c) 3/8 (d) 7/8
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/12 (c) 1/36 (d) 1/18
16. 16.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
17. 17.Three coins are tossed together. What is the probability of getting exactly one head? (a) 5/8 (b) 3/5 (c) 3/8 (d) 1/4
18. 18.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 4/11 (b) 1/9 (c) 1/11 (d) 5/36
19. 19.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
20. 20.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
21. 21.A bag has 7 yellow, 7 green and 2 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 5/8 (b) 1/3 (c) 7/16 (d) 9/16
22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 1/11 (c) 5/36 (d) 1/6
23. 23.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
24. 24.A bag has 4 white, 5 green and 6 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 1/15 (c) 11/15 (d) 2/3
25. 25.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
26. 26.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 1/12 (c) 3/11 (d) 1/11
27. 27.A bag has 6 red, 9 yellow and 2 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 2/17 (b) 1/3 (c) 16/17 (d) 15/17
28. 28.A bag has 4 red, 3 yellow and 3 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/10 (b) 1/3 (c) 3/10 (d) 3/7
29. 29.A bag has 9 red, 6 green and 2 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 16/17 (c) 2/17 (d) 15/17
30. 30.A bag has 3 blue, 9 red and 2 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 3/14 (c) 11/14 (d) 3/11
31. 31.A bag has 4 red, 4 green and 3 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 7/11 (b) 4/11 (c) 4/7 (d) 1/3
32. 32.A bag has 9 yellow, 8 white and 3 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 3/5 (c) 11/20 (d) 9/20
33. 33.A bag has 8 blue, 8 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) 8/21 (c) 13/21 (d) 2/3
34. 34.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
35. 35.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/7 (b) 1/8 (c) 1/4 (d) 7/8
36. 36.A bag has 4 red, 7 blue and 5 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 1/4 (c) 13/16 (d) 3/4
37. 37.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 5/6 (b) 1/5 (c) 1/3 (d) 1/6
38. 38.A bag has 6 yellow, 4 blue and 5 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/5 (b) 1/2 (c) 1/3 (d) 2/3
39. 39.A bag has 8 blue, 8 green and 5 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 16/21 (b) 1/3 (c) 17/21 (d) 5/21
40. 40.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

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