Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 970 · 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 8 red, 5 blue and 7 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/5 (b) 3/5 (c) 1/3 (d) 2/3
2. 2.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/2 (c) 1/3 (d) 3/4
3. 3.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/2 (c) 3/4 (d) 1/3
4. 4.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
5. 5.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/4
6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/18 (b) 1/11 (c) 1/36 (d) 1/12
7. 7.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 1/2 (c) 2/3 (d) 1/3
8. 8.A bag has 8 green, 2 yellow and 4 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 6/7 (b) 1/3 (c) 1/7 (d) 1/6
9. 9.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/4 (b) 5/6 (c) 2/3 (d) 1/3
10. 10.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
11. 11.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 5/8 (c) 3/8 (d) 1/4
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/11 (b) 4/11 (c) 1/9 (d) 5/36
13. 13.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 4/11 (c) 1/11 (d) 1/9
14. 14.A bag has 3 yellow, 5 white and 9 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 9/17 (b) 10/17 (c) 1/3 (d) 8/17
15. 15.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/8 (b) 1/4 (c) 3/4 (d) 3/8
16. 16.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
17. 17.A bag has 4 green, 8 red and 4 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/16 (b) 1/2 (c) 1/3 (d) 9/16
18. 18.A bag has 5 green, 2 blue and 7 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/14 (b) 4/7 (c) 1/2 (d) 1/3
19. 19.A bag has 9 red, 4 green and 7 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/4 (b) 1/5 (c) 1/3 (d) 4/5
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/12 (b) 1/36 (c) 1/11 (d) 1/18
21. 21.A bag has 3 white, 7 blue and 9 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 3/19 (b) 1/3 (c) 17/19 (d) 16/19
22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 2/11 (b) 1/12 (c) 1/11 (d) 1/18
23. 23.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 5/6 (b) 1/3 (c) 1/5 (d) 1/6
24. 24.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
25. 25.A bag has 2 green, 7 red and 4 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 4/9 (b) 4/13 (c) 1/3 (d) 9/13
26. 26.A bag has 3 white, 4 yellow and 9 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 13/16 (b) 3/4 (c) 1/4 (d) 1/3
27. 27.A bag has 3 yellow, 3 green and 2 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 5/8 (b) 1/3 (c) 3/5 (d) 3/8
28. 28.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/7 (b) 1/4 (c) 7/8 (d) 1/8
29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 7/36 (b) 1/6 (c) 6/11 (d) 1/11
30. 30.A bag has 3 blue, 7 red and 6 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 11/16 (b) 1/3 (c) 3/8 (d) 5/8
31. 31.A bag has 9 blue, 2 yellow and 3 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/14 (b) 1/3 (c) 11/14 (d) 6/7
32. 32.A bag has 9 yellow, 9 red and 9 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/27 (b) 19/27 (c) 2/3 (d) 1/3
33. 33.A bag has 6 yellow, 4 blue and 8 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 2/3 (b) 1/3 (c) 1/18 (d) 13/18
34. 34.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
35. 35.A bag has 6 green, 2 blue and 2 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 9/10 (b) 1/3 (c) 1/5 (d) 4/5
36. 36.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/3 (b) 1/5 (c) 5/6 (d) 1/6
37. 37.A bag has 3 red, 3 white and 9 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/4 (b) 1/5 (c) 1/3 (d) 4/5
38. 38.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
39. 39.A bag has 6 yellow, 8 blue and 4 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/18 (b) 13/18 (c) 1/3 (d) 2/3
40. 40.A bag has 6 blue, 5 green and 9 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 11/20 (b) 9/20 (c) 1/3 (d) 3/5

Free maths olympiad lessons, practice and worksheets at talentjr.in/maths-olympiad