Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 400 · 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) 2/3 (c) 1/3 (d) 5/6
2. 2.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/5 (c) 3/8 (d) 5/8
3. 3.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
4. 4.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
5. 5.A bag has 8 green, 7 white and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 4/5 (b) 1/3 (c) 1/4 (d) 3/4
6. 6.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/4 (b) 1/3 (c) 5/6 (d) 2/3
7. 7.A bag has 4 white, 9 green and 2 blue balls. One ball is taken out without looking. What is the probability that it is not white? (a) 4/5 (b) 1/3 (c) 11/15 (d) 4/15
8. 8.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
9. 9.A bag has 2 white, 9 yellow and 3 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 1/7 (c) 1/6 (d) 6/7
10. 10.A bag has 3 green, 5 white and 9 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 9/17 (c) 8/17 (d) 8/9
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/6 (b) 1/11 (c) 5/36 (d) 5/11
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/9 (b) 4/11 (c) 5/36 (d) 1/11
13. 13.A bag has 3 red, 6 blue and 4 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 11/13 (b) 1/3 (c) 3/13 (d) 10/13
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 6/11 (b) 1/6 (c) 7/36 (d) 1/11
15. 15.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/2 (c) 3/4 (d) 1/3
16. 16.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/4
17. 17.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
18. 18.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 1/3 (c) 2/3 (d) 1/2
19. 19.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/2 (c) 1/4 (d) 3/4
20. 20.A bag has 4 red, 4 green and 4 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/12 (b) 1/3 (c) 1/2 (d) 2/3
21. 21.A bag has 3 blue, 2 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 11/13 (c) 2/11 (d) 2/13
22. 22.A bag has 7 red, 7 green and 9 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 7/23 (c) 16/23 (d) 17/23
23. 23.A bag has 3 green, 4 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 4/15 (b) 11/15 (c) 1/3 (d) 4/11
24. 24.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
25. 25.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
26. 26.A bag has 5 green, 6 yellow and 8 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 6/19 (c) 13/19 (d) 14/19
27. 27.A bag has 9 blue, 7 white and 9 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 16/25 (c) 9/25 (d) 17/25
28. 28.A bag has 6 red, 4 blue and 5 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 2/5 (b) 1/3 (c) 2/3 (d) 1/2
29. 29.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/3 (b) 1/5 (c) 5/6 (d) 1/6
30. 30.A bag has 5 green, 5 red and 6 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 5/16 (c) 11/16 (d) 3/4
31. 31.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
32. 32.A bag has 2 yellow, 3 white and 3 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/5 (b) 5/8 (c) 3/8 (d) 1/3
33. 33.A bag has 2 yellow, 8 green and 9 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 9/10 (c) 10/19 (d) 9/19
34. 34.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 1/4 (c) 7/8 (d) 3/8
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 3/11 (c) 1/11 (d) 1/9
36. 36.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
37. 37.A bag has 6 red, 8 yellow and 7 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 2/3 (b) 1/3 (c) 13/21 (d) 8/21
38. 38.A bag has 7 yellow, 5 white and 8 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/13 (b) 13/20 (c) 7/20 (d) 1/3
39. 39.A bag has 5 white, 9 blue and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 9/22 (b) 1/3 (c) 7/11 (d) 13/22
40. 40.A bag has 4 blue, 7 white and 9 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 3/5 (b) 1/3 (c) 9/20 (d) 11/20

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