Probability Worksheet for Class 8 Maths Olympiad

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

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