Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 117 · 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 an odd number? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
2. 2.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/7 (c) 1/4 (d) 1/8
3. 3.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/3 (b) 1/2 (c) 3/4 (d) 1/4
4. 4.A bag has 4 blue, 6 red and 9 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 13/19 (b) 14/19 (c) 1/3 (d) 6/19
5. 5.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/2 (b) 1/4 (c) 1/3 (d) 3/4
6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/11 (b) 1/6 (c) 5/36 (d) 5/11
7. 7.A bag has 5 yellow, 6 red and 4 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 11/15 (b) 2/3 (c) 1/3 (d) 1/15
8. 8.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/5 (b) 5/6 (c) 1/6 (d) 1/3
9. 9.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
10. 10.A bag has 6 blue, 2 yellow and 3 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 3/11 (b) 8/11 (c) 1/3 (d) 9/11
11. 11.A bag has 9 white, 5 blue and 7 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 8/21 (b) 1/3 (c) 1/2 (d) 2/3
12. 12.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/8 (b) 3/8 (c) 1/4 (d) 3/4
13. 13.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/4 (b) 1/3 (c) 5/6 (d) 2/3
14. 14.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
15. 15.A bag has 9 red, 6 green and 3 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/5 (b) 5/6 (c) 1/3 (d) 1/6
16. 16.A bag has 5 blue, 4 green and 8 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 10/17 (b) 1/3 (c) 8/17 (d) 9/17
17. 17.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
18. 18.Two coins are tossed together. What is the probability of getting exactly one head? (a) 2/3 (b) 1/4 (c) 1/2 (d) 1/3
19. 19.A bag has 4 white, 6 red and 3 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 6/7 (b) 7/13 (c) 6/13 (d) 1/3
20. 20.A bag has 4 yellow, 9 blue and 7 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 7/13 (b) 7/20 (c) 13/20 (d) 1/3
21. 21.A bag has 5 blue, 6 green and 2 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 9/13 (b) 8/13 (c) 1/3 (d) 5/13
22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/11 (b) 1/18 (c) 1/12 (d) 2/11
23. 23.A bag has 3 green, 6 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 6/11 (b) 6/17 (c) 11/17 (d) 1/3
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 7/36 (c) 1/11 (d) 6/11
25. 25.A bag has 4 blue, 6 red and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 11/14 (b) 1/3 (c) 5/7 (d) 2/7
26. 26.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/9 (b) 3/11 (c) 1/11 (d) 1/12
27. 27.A bag has 5 yellow, 2 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 3/7 (b) 1/3 (c) 7/10 (d) 3/10
28. 28.A bag has 5 red, 9 white and 8 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/17 (b) 1/3 (c) 17/22 (d) 5/22
29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/11 (b) 5/36 (c) 5/11 (d) 1/6
30. 30.A bag has 5 yellow, 7 green and 7 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 14/19 (b) 5/19 (c) 1/3 (d) 5/14
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/11 (b) 1/12 (c) 3/11 (d) 1/9
32. 32.A bag has 9 green, 7 white and 2 blue balls. One ball is taken out without looking. What is the probability that it is not white? (a) 2/3 (b) 11/18 (c) 7/18 (d) 1/3
33. 33.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
34. 34.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/36 (b) 1/18 (c) 1/12 (d) 1/11
35. 35.Three coins are tossed together. What is the probability of getting exactly one head? (a) 5/8 (b) 3/8 (c) 3/5 (d) 1/4
36. 36.A bag has 8 blue, 4 green and 2 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 3/7 (b) 1/3 (c) 4/7 (d) 3/4
37. 37.A bag has 3 red, 3 white and 4 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/5 (b) 2/5 (c) 1/3 (d) 2/3
38. 38.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/8 (c) 3/8 (d) 7/8
39. 39.A bag has 6 red, 3 yellow and 5 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 9/14 (b) 1/3 (c) 3/7 (d) 4/7
40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/12 (b) 1/11 (c) 2/11 (d) 1/18

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