Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 63 · 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 a prime number? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
2. 2.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/2 (b) 1/6 (c) 2/3 (d) 1/3
3. 3.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
4. 4.Three coins are tossed together. What is the probability of getting exactly one head? (a) 5/8 (b) 3/5 (c) 3/8 (d) 1/4
5. 5.A bag has 9 white, 6 yellow and 2 blue balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 6/17 (b) 12/17 (c) 11/17 (d) 1/3
6. 6.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 3/8 (c) 1/8 (d) 7/8
7. 7.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 2/3 (b) 1/3 (c) 1/4 (d) 1/2
8. 8.A bag has 7 blue, 3 yellow and 5 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 2/3 (c) 11/15 (d) 1/15
9. 9.A bag has 3 blue, 8 red and 7 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 4/9 (c) 4/5 (d) 5/9
10. 10.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 2/3 (c) 1/3 (d) 1/2
11. 11.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 5/6 (c) 1/4 (d) 1/3
12. 12.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 3/4 (c) 1/8 (d) 3/8
13. 13.A bag has 6 yellow, 5 red and 9 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 3/10 (b) 3/4 (c) 7/10 (d) 1/3
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/12 (b) 1/11 (c) 1/18 (d) 2/11
15. 15.A bag has 3 red, 4 blue and 2 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 8/9 (c) 7/9 (d) 2/9
16. 16.A bag has 9 white, 6 red and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 10/19 (b) 9/19 (c) 11/19 (d) 1/3
17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 2/11 (b) 1/18 (c) 1/11 (d) 1/12
18. 18.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
19. 19.A bag has 9 blue, 6 red and 6 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 5/7 (c) 2/7 (d) 2/5
20. 20.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) 5/18 (b) 1/3 (c) 7/9 (d) 13/18
21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/11 (b) 5/11 (c) 1/6 (d) 5/36
22. 22.A bag has 4 blue, 3 green and 7 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 4/7 (b) 1/3 (c) 1/14 (d) 1/2
23. 23.A bag has 9 blue, 9 green and 3 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 6/7 (b) 1/6 (c) 1/3 (d) 1/7
24. 24.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
25. 25.A bag has 2 green, 6 blue and 3 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 10/11 (b) 9/11 (c) 2/11 (d) 1/3
26. 26.A bag has 4 blue, 2 red and 4 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/5 (b) 2/3 (c) 1/3 (d) 2/5
27. 27.Two coins are tossed together. What is the probability of getting at least one head? (a) 3/4 (b) 1/3 (c) 1/2 (d) 1/4
28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 1/12 (c) 3/11 (d) 1/11
29. 29.A bag has 3 yellow, 5 red and 4 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 5/6 (b) 3/4 (c) 1/4 (d) 1/3
30. 30.A bag has 6 red, 9 blue and 6 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 2/7 (c) 16/21 (d) 5/7
31. 31.A bag has 7 yellow, 8 white and 9 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 5/8 (b) 3/8 (c) 2/3 (d) 1/3
32. 32.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/3 (b) 1/4 (c) 5/6 (d) 2/3
33. 33.A bag has 3 red, 3 yellow and 6 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 3/4 (c) 1/4 (d) 1/12
34. 34.A bag has 4 red, 3 yellow and 4 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 3/11 (c) 8/11 (d) 9/11
35. 35.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
36. 36.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/36 (c) 1/11 (d) 1/12
37. 37.A bag has 4 red, 6 green and 4 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/5 (b) 1/3 (c) 2/7 (d) 5/7
38. 38.A bag has 8 white, 2 red and 9 blue balls. One ball is taken out without looking. What is the probability that it is not white? (a) 8/19 (b) 1/3 (c) 11/19 (d) 12/19
39. 39.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
40. 40.A bag has 6 red, 2 blue and 7 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 13/15 (b) 1/3 (c) 14/15 (d) 2/15

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