Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 287 · 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 7 white, 2 red and 4 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 12/13 (b) 2/13 (c) 1/3 (d) 11/13
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 4/11 (b) 1/9 (c) 5/36 (d) 1/11
3. 3.A bag has 3 red, 5 yellow and 3 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 6/11 (b) 1/3 (c) 5/11 (d) 5/6
4. 4.A bag has 6 red, 9 blue and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 1/4 (c) 3/4 (d) 4/5
5. 5.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/18 (c) 1/36 (d) 1/12
6. 6.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 3/4 (b) 1/2 (c) 1/3 (d) 1/4
7. 7.A bag has 3 blue, 7 green and 6 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/8 (b) 3/5 (c) 1/3 (d) 3/8
8. 8.A bag has 3 red, 2 white and 4 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/9 (b) 2/3 (c) 7/9 (d) 1/3
9. 9.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
10. 10.A bag has 5 white, 2 red and 7 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 9/14 (b) 5/14 (c) 1/3 (d) 5/9
11. 11.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
12. 12.A bag has 9 red, 6 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 5/6 (c) 1/6 (d) 8/9
13. 13.A bag has 9 blue, 3 yellow and 7 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 9/19 (b) 11/19 (c) 10/19 (d) 1/3
14. 14.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 2/3 (c) 1/2 (d) 1/6
15. 15.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 3/8 (c) 3/4 (d) 1/8
16. 16.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
17. 17.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
18. 18.A bag has 8 green, 6 white and 7 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 8/21 (b) 1/3 (c) 13/21 (d) 8/13
19. 19.A bag has 3 blue, 4 green and 8 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 4/15 (c) 4/11 (d) 11/15
20. 20.A bag has 7 green, 7 yellow and 6 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 7/10 (b) 3/7 (c) 3/10 (d) 1/3
21. 21.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
22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/18 (b) 1/12 (c) 1/11 (d) 2/11
23. 23.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 5/6 (c) 1/3 (d) 1/4
24. 24.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
25. 25.A bag has 5 blue, 2 yellow and 6 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/13 (b) 8/13 (c) 1/3 (d) 5/8
26. 26.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 5/6 (b) 1/3 (c) 1/4 (d) 2/3
27. 27.A bag has 4 yellow, 6 green and 3 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 7/13 (c) 6/13 (d) 6/7
28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 5/36 (b) 1/11 (c) 1/9 (d) 4/11
29. 29.A bag has 3 red, 6 yellow and 5 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/14 (b) 6/7 (c) 11/14 (d) 1/3
30. 30.A bag has 5 red, 9 white and 2 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 7/8 (c) 1/7 (d) 1/8
31. 31.A bag has 5 green, 3 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 15/17 (b) 14/17 (c) 1/3 (d) 3/17
32. 32.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
33. 33.A bag has 9 green, 8 yellow and 2 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 10/19 (b) 1/3 (c) 9/10 (d) 9/19
34. 34.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 5/8 (c) 3/5 (d) 1/4
35. 35.A bag has 7 blue, 9 yellow and 4 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 13/20 (c) 7/20 (d) 7/13
36. 36.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
37. 37.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/6 (b) 1/5 (c) 5/6 (d) 1/3
38. 38.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
39. 39.A bag has 8 white, 7 red and 6 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 5/7 (b) 16/21 (c) 2/7 (d) 1/3
40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/36 (b) 1/11 (c) 1/6 (d) 5/11

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