Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 238 · 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 green, 7 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 7/16 (b) 1/3 (c) 7/9 (d) 9/16
2. 2.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 2/3 (b) 1/4 (c) 5/6 (d) 1/3
3. 3.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 blue? (a) 7/17 (b) 11/17 (c) 10/17 (d) 1/3
4. 4.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 1/3 (c) 2/3 (d) 1/2
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/9 (b) 1/11 (c) 1/12 (d) 3/11
6. 6.A bag has 9 red, 2 blue and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 11/19 (b) 9/19 (c) 10/19 (d) 1/3
7. 7.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
8. 8.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
9. 9.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/2 (b) 1/6 (c) 1/3 (d) 2/3
10. 10.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
11. 11.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
12. 12.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
13. 13.A bag has 5 red, 5 blue and 2 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 5/6 (c) 1/6 (d) 1/5
14. 14.A bag has 4 green, 2 blue and 8 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/7 (b) 1/3 (c) 5/7 (d) 2/5
15. 15.Three coins are tossed together. What is the probability of getting at least one head? (a) 7/8 (b) 1/8 (c) 3/8 (d) 1/4
16. 16.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 1/4 (c) 2/3 (d) 5/6
17. 17.A bag has 2 yellow, 4 green and 8 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 4/7 (b) 1/3 (c) 3/7 (d) 9/14
18. 18.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/3 (b) 1/4 (c) 1/2 (d) 2/3
19. 19.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/6 (b) 5/11 (c) 1/11 (d) 5/36
20. 20.A bag has 6 yellow, 5 blue and 4 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 2/3 (b) 3/5 (c) 2/5 (d) 1/3
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 3/11 (c) 1/11 (d) 1/12
22. 22.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/3 (b) 1/6 (c) 5/6 (d) 1/5
23. 23.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/2 (b) 1/3 (c) 3/4 (d) 1/4
24. 24.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/3 (c) 1/2 (d) 3/4
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 6/11 (b) 1/6 (c) 1/11 (d) 7/36
26. 26.A bag has 8 green, 9 yellow and 4 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 17/21 (b) 1/3 (c) 4/21 (d) 6/7
27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/11 (b) 5/36 (c) 4/11 (d) 1/9
28. 28.A bag has 9 blue, 9 yellow and 2 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/10 (b) 9/10 (c) 1/3 (d) 1/9
29. 29.A bag has 4 green, 5 white and 9 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 1/18 (c) 1/2 (d) 5/9
30. 30.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 4/11 (b) 1/11 (c) 5/36 (d) 1/9
31. 31.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
32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 2/11 (b) 1/11 (c) 1/12 (d) 1/18
33. 33.A bag has 7 white, 7 yellow and 8 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/11 (b) 1/3 (c) 4/7 (d) 4/11
34. 34.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 2/11 (b) 1/12 (c) 1/18 (d) 1/11
36. 36.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/4 (b) 1/4 (c) 1/8 (d) 3/8
37. 37.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/3 (b) 1/4 (c) 5/6 (d) 2/3
38. 38.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
39. 39.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
40. 40.A bag has 6 red, 3 blue and 2 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 2/11 (c) 9/11 (d) 2/9

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