Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 646 · 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 9 yellow, 3 green and 6 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/2 (b) 7/18 (c) 2/3 (d) 1/3
2. 2.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
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/12 (b) 2/11 (c) 1/18 (d) 1/11
4. 4.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 1/3 (c) 5/6 (d) 1/4
5. 5.A bag has 4 green, 6 red and 6 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 5/8 (b) 3/5 (c) 3/8 (d) 1/3
6. 6.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
7. 7.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
8. 8.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 3/4 (c) 1/3 (d) 1/2
9. 9.A bag has 6 red, 7 green and 8 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 8/21 (b) 13/21 (c) 1/3 (d) 2/3
10. 10.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 1/4 (c) 1/3 (d) 2/3
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 1/11 (c) 4/11 (d) 1/9
12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 1/6 (c) 5/36 (d) 1/11
13. 13.A bag has 6 yellow, 3 red and 9 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/5 (b) 1/3 (c) 1/6 (d) 5/6
14. 14.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/2 (c) 1/4 (d) 3/4
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.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
17. 17.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
18. 18.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/2 (b) 2/3 (c) 1/3 (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.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/36 (c) 1/12 (d) 1/11
21. 21.A bag has 2 green, 2 white and 4 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/4 (b) 1/4 (c) 3/8 (d) 1/3
22. 22.A bag has 9 blue, 2 yellow and 8 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 11/19 (b) 8/11 (c) 1/3 (d) 8/19
23. 23.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/11 (b) 1/6 (c) 6/11 (d) 7/36
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/12 (c) 1/11 (d) 1/9
25. 25.A bag has 7 blue, 2 white and 6 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 13/15 (b) 2/15 (c) 1/3 (d) 2/13
26. 26.A bag has 5 yellow, 9 red and 4 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 7/9 (b) 1/3 (c) 2/9 (d) 5/6
27. 27.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
28. 28.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
29. 29.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/3 (b) 1/4 (c) 2/3 (d) 5/6
30. 30.A bag has 9 yellow, 7 red and 8 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/5 (b) 3/8 (c) 5/8 (d) 1/3
31. 31.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/5 (c) 5/8 (d) 3/8
32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 5/36 (b) 1/9 (c) 1/11 (d) 4/11
33. 33.A bag has 8 red, 7 blue and 6 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 13/21 (b) 8/21 (c) 1/3 (d) 8/13
34. 34.A bag has 8 white, 5 yellow and 9 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 7/11 (b) 9/22 (c) 1/3 (d) 13/22
35. 35.A bag has 8 green, 3 blue and 2 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 8/13 (b) 5/13 (c) 1/3 (d) 9/13
36. 36.A bag has 9 green, 3 white and 5 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 14/17 (c) 3/14 (d) 3/17
37. 37.A bag has 2 blue, 7 green and 6 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/15 (b) 1/3 (c) 7/8 (d) 8/15
38. 38.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 3/11 (c) 1/9 (d) 1/11
39. 39.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/7 (c) 1/8 (d) 1/4
40. 40.A bag has 5 red, 7 white and 7 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 7/12 (c) 7/19 (d) 12/19

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