Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 437 · 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 bag has 6 blue, 5 white and 4 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/5 (b) 3/5 (c) 1/3 (d) 2/3
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 2/11 (b) 1/11 (c) 1/12 (d) 1/18
3. 3.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/8 (b) 3/4 (c) 1/4 (d) 3/8
4. 4.Three coins are tossed together. What is the probability of getting at least one head? (a) 7/8 (b) 1/4 (c) 3/8 (d) 1/8
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/11 (b) 1/9 (c) 1/12 (d) 3/11
6. 6.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/6 (b) 5/36 (c) 5/11 (d) 1/11
8. 8.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/2 (b) 2/3 (c) 1/4 (d) 1/3
9. 9.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 5/8 (c) 3/5 (d) 3/8
10. 10.A bag has 2 green, 8 red and 6 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/8 (b) 1/7 (c) 7/8 (d) 1/3
11. 11.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
12. 12.A bag has 9 green, 7 blue and 2 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 1/18 (c) 5/9 (d) 1/2
13. 13.A bag has 4 white, 9 green and 4 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 4/17 (b) 1/3 (c) 4/13 (d) 13/17
14. 14.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 2/3 (c) 1/2 (d) 1/6
15. 15.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 1/4 (c) 2/3 (d) 1/2
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/12 (b) 1/18 (c) 1/36 (d) 1/11
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/11 (b) 5/36 (c) 1/9 (d) 4/11
18. 18.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/3 (c) 3/4 (d) 1/2
19. 19.A bag has 3 green, 8 white and 3 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 11/14 (b) 1/3 (c) 3/11 (d) 3/14
20. 20.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
21. 21.A bag has 4 blue, 9 white and 2 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 2/15 (b) 14/15 (c) 1/3 (d) 13/15
22. 22.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/8 (b) 7/8 (c) 1/4 (d) 1/7
23. 23.A bag has 4 green, 8 yellow and 9 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 13/21 (b) 2/3 (c) 1/3 (d) 8/21
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/18 (b) 2/11 (c) 1/11 (d) 1/12
25. 25.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 5/6 (b) 1/3 (c) 1/5 (d) 1/6
26. 26.A bag has 7 red, 2 green and 9 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 7/18 (c) 2/3 (d) 11/18
27. 27.A bag has 4 red, 7 white and 3 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/2 (b) 1/14 (c) 4/7 (d) 1/3
28. 28.A bag has 4 green, 3 white and 2 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/9 (b) 7/9 (c) 1/3 (d) 2/3
29. 29.A bag has 2 blue, 9 green and 4 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 3/5 (b) 2/3 (c) 1/3 (d) 2/5
30. 30.A bag has 3 green, 4 yellow and 4 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 4/11 (c) 7/11 (d) 4/7
31. 31.A bag has 2 white, 3 green and 2 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 3/7 (b) 5/7 (c) 4/7 (d) 1/3
32. 32.A bag has 2 green, 4 yellow and 9 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 4/11 (b) 11/15 (c) 1/3 (d) 4/15
33. 33.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/6
34. 34.A bag has 6 blue, 9 red and 8 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 9/23 (b) 15/23 (c) 1/3 (d) 14/23
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 5/36 (c) 1/6 (d) 1/11
36. 36.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
37. 37.A bag has 5 red, 6 white and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 5/8 (b) 11/16 (c) 3/8 (d) 1/3
38. 38.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 1/3 (c) 1/4 (d) 2/3
39. 39.A bag has 5 green, 5 white and 3 blue balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 8/13 (c) 5/13 (d) 9/13
40. 40.A bag has 9 green, 9 white and 2 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 9/11 (c) 11/20 (d) 9/20

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