Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 48 · 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 even number? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
2. 2.A bag has 5 yellow, 3 white and 6 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 9/14 (b) 5/7 (c) 1/3 (d) 5/14
3. 3.A bag has 6 blue, 3 red and 4 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 6/7 (b) 1/3 (c) 6/13 (d) 7/13
4. 4.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/9 (b) 1/11 (c) 4/11 (d) 5/36
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 7/36 (c) 6/11 (d) 1/11
6. 6.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/6 (b) 1/3 (c) 5/6 (d) 1/5
7. 7.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 5/6 (b) 2/3 (c) 1/4 (d) 1/3
8. 8.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 5/6 (b) 1/3 (c) 2/3 (d) 1/4
9. 9.A bag has 9 green, 9 white and 8 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 9/13 (b) 19/26 (c) 1/3 (d) 4/13
10. 10.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
11. 11.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
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.Two coins are tossed together. What is the probability of getting exactly one head? (a) 2/3 (b) 1/4 (c) 1/3 (d) 1/2
14. 14.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/4 (b) 2/3 (c) 5/6 (d) 1/3
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/11 (b) 1/6 (c) 5/11 (d) 5/36
16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 1/11 (c) 1/6 (d) 5/36
17. 17.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
18. 18.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/6 (b) 1/2 (c) 2/3 (d) 1/3
19. 19.A bag has 2 yellow, 8 blue and 3 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 10/13 (c) 3/13 (d) 11/13
20. 20.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
21. 21.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/3 (c) 1/2 (d) 3/4
22. 22.A bag has 3 blue, 3 white and 7 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 10/13 (b) 1/3 (c) 3/13 (d) 3/10
23. 23.A bag has 2 green, 8 blue and 2 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 1/6 (c) 5/6 (d) 11/12
24. 24.A bag has 9 red, 5 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 10/17 (c) 9/17 (d) 8/17
25. 25.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 3/8 (c) 1/4 (d) 5/8
26. 26.A bag has 7 white, 7 yellow and 3 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 15/17 (b) 1/3 (c) 3/17 (d) 14/17
27. 27.A bag has 3 green, 8 blue and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 13/15 (b) 4/5 (c) 1/5 (d) 1/3
28. 28.A bag has 8 red, 2 blue and 6 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/8 (b) 3/8 (c) 1/3 (d) 3/5
29. 29.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
30. 30.A bag has 4 yellow, 9 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) 5/18 (c) 13/18 (d) 7/9
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/12 (c) 1/36 (d) 1/18
32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/11 (c) 1/12 (d) 1/9
33. 33.A bag has 2 red, 3 blue and 4 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 4/9 (b) 1/2 (c) 1/3 (d) 2/3
34. 34.A bag has 6 yellow, 3 red and 4 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 8/13 (b) 7/13 (c) 6/13 (d) 1/3
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/36 (c) 1/12 (d) 1/18
36. 36.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 1/3 (c) 1/6 (d) 2/3
37. 37.A bag has 7 blue, 6 red and 4 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 4/17 (c) 14/17 (d) 13/17
38. 38.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 1/4 (c) 1/3 (d) 3/4
39. 39.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
40. 40.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 green? (a) 1/3 (b) 3/17 (c) 15/17 (d) 14/17

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