Probability Worksheet for Class 8 Maths Olympiad

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

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