Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 414 · 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) 1/11 (d) 5/36
2. 2.A bag has 7 blue, 2 yellow and 5 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/6 (b) 6/7 (c) 1/3 (d) 1/7
3. 3.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
4. 4.A bag has 9 red, 8 green and 5 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 17/22 (b) 9/11 (c) 1/3 (d) 5/22
5. 5.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
6. 6.A bag has 5 white, 8 green and 2 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/3 (b) 1/2 (c) 1/3 (d) 2/5
7. 7.A bag has 7 yellow, 8 blue and 7 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 7/15 (b) 15/22 (c) 7/22 (d) 1/3
8. 8.A bag has 4 red, 9 green and 2 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 2/3 (b) 1/3 (c) 3/5 (d) 2/5
9. 9.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
10. 10.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 1/4 (c) 1/3 (d) 2/3
11. 11.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/11 (b) 3/11 (c) 1/12 (d) 1/9
13. 13.A bag has 9 white, 2 green and 5 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 1/8 (c) 7/8 (d) 1/7
14. 14.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
15. 15.A bag has 3 red, 7 white and 5 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/4 (b) 1/5 (c) 1/3 (d) 4/5
16. 16.A bag has 6 red, 3 blue and 7 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 3/5 (c) 5/8 (d) 3/8
17. 17.A bag has 2 white, 9 blue and 2 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 12/13 (c) 11/13 (d) 2/13
18. 18.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
19. 19.A bag has 5 green, 7 red and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 7/16 (c) 5/8 (d) 9/16
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.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/18 (b) 2/11 (c) 1/11 (d) 1/12
22. 22.A bag has 7 green, 8 blue and 5 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 13/20 (b) 1/3 (c) 3/5 (d) 2/5
23. 23.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 5/6 (c) 1/3 (d) 1/4
24. 24.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) 1/8 (d) 1/4
25. 25.A bag has 6 white, 5 green and 2 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 6/7 (c) 6/13 (d) 7/13
26. 26.A bag has 5 green, 4 white and 8 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 13/17 (b) 4/17 (c) 1/3 (d) 14/17
27. 27.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 3/4 (c) 1/2 (d) 1/4
28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/11 (b) 5/36 (c) 5/11 (d) 1/6
29. 29.A bag has 7 green, 3 white and 7 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/17 (b) 1/3 (c) 14/17 (d) 3/14
30. 30.A bag has 4 red, 8 green and 9 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 13/21 (b) 1/3 (c) 8/21 (d) 2/3
31. 31.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/8 (b) 1/7 (c) 7/8 (d) 1/4
32. 32.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/3 (b) 1/6 (c) 5/6 (d) 1/5
33. 33.A bag has 2 blue, 5 white and 5 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 5/12 (c) 5/7 (d) 7/12
34. 34.A bag has 8 white, 8 blue and 9 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 18/25 (b) 17/25 (c) 1/3 (d) 8/25
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 1/9 (c) 1/11 (d) 3/11
36. 36.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/4 (b) 1/3 (c) 2/3 (d) 5/6
37. 37.A bag has 2 green, 4 blue and 4 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 7/10 (b) 2/5 (c) 3/5 (d) 1/3
38. 38.A bag has 5 red, 5 green and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 9/14 (b) 5/14 (c) 1/3 (d) 5/7
39. 39.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/3 (c) 1/2 (d) 3/4
40. 40.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/8 (c) 5/8 (d) 3/5

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