Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 804 · 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 2 yellow, 5 white and 2 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/9 (b) 2/9 (c) 1/3 (d) 2/7
2. 2.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 1/18 (c) 1/11 (d) 2/11
4. 4.A bag has 5 red, 9 yellow and 5 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 10/19 (b) 1/3 (c) 11/19 (d) 9/19
5. 5.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
6. 6.A bag has 2 green, 9 white and 2 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 4/9 (b) 9/13 (c) 4/13 (d) 1/3
7. 7.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 1/4 (c) 5/8 (d) 3/5
8. 8.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 1/3 (c) 1/4 (d) 2/3
9. 9.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/4
10. 10.A bag has 9 yellow, 7 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 7/25 (b) 1/3 (c) 18/25 (d) 19/25
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/11 (b) 4/11 (c) 5/36 (d) 1/9
12. 12.A bag has 7 white, 8 green and 2 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 8/9 (b) 1/3 (c) 8/17 (d) 9/17
13. 13.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 2/11 (b) 1/12 (c) 1/18 (d) 1/11
14. 14.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
15. 15.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 5/6 (b) 1/4 (c) 1/3 (d) 2/3
16. 16.A bag has 4 yellow, 3 green and 9 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 7/9 (c) 9/16 (d) 7/16
17. 17.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/8 (b) 3/4 (c) 1/8 (d) 1/4
18. 18.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/11 (b) 1/6 (c) 5/36 (d) 5/11
19. 19.A bag has 6 yellow, 9 blue and 5 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 7/10 (c) 3/4 (d) 3/10
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 4/11 (b) 5/36 (c) 1/11 (d) 1/9
21. 21.A bag has 2 white, 3 blue and 3 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 5/8 (c) 3/5 (d) 3/8
22. 22.A bag has 2 white, 7 blue and 5 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 4/7 (b) 1/2 (c) 1/3 (d) 1/14
23. 23.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
24. 24.A bag has 9 white, 4 red and 3 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 13/16 (b) 3/13 (c) 1/3 (d) 3/16
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/36 (b) 1/12 (c) 1/11 (d) 1/18
26. 26.A bag has 4 red, 6 blue and 7 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 4/13 (b) 1/3 (c) 13/17 (d) 4/17
27. 27.A bag has 5 green, 4 white and 6 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 4/15 (b) 1/3 (c) 4/11 (d) 11/15
28. 28.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
29. 29.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/5 (b) 1/3 (c) 1/6 (d) 5/6
30. 30.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/8 (c) 7/8 (d) 3/8
31. 31.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 1/3 (c) 1/4 (d) 3/4
32. 32.A bag has 7 white, 3 green and 3 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 3/13 (c) 11/13 (d) 10/13
33. 33.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/4 (c) 1/8 (d) 1/7
34. 34.A bag has 5 red, 9 green and 4 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/18 (b) 13/18 (c) 5/13 (d) 1/3
35. 35.A bag has 2 blue, 8 red and 4 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 6/7 (b) 1/6 (c) 1/7 (d) 1/3
36. 36.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/2 (b) 1/3 (c) 1/4 (d) 3/4
37. 37.A bag has 8 blue, 8 yellow and 9 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 18/25 (b) 17/25 (c) 1/3 (d) 8/25
38. 38.A bag has 5 green, 8 red and 4 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 8/9 (b) 9/17 (c) 1/3 (d) 8/17
39. 39.A bag has 4 blue, 4 red and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 4/13 (b) 10/13 (c) 9/13 (d) 1/3
40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 3/11 (c) 1/12 (d) 1/11

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