Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 278 · 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 red, 7 yellow and 6 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 6/13 (b) 6/19 (c) 13/19 (d) 1/3
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/11 (b) 5/36 (c) 5/11 (d) 1/6
3. 3.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) 1/2 (d) 1/4
4. 4.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 3/11 (c) 1/12 (d) 1/11
5. 5.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/8 (c) 1/7 (d) 1/4
6. 6.A bag has 6 red, 2 white and 9 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 16/17 (b) 15/17 (c) 2/17 (d) 1/3
7. 7.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 3/4 (c) 1/4 (d) 1/3
8. 8.Two coins are tossed together. What is the probability of getting exactly one head? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/4
9. 9.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
10. 10.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/12 (b) 1/18 (c) 1/11 (d) 1/36
11. 11.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) 3/8 (d) 1/8
12. 12.A bag has 2 red, 5 blue and 8 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/5 (b) 2/3 (c) 1/3 (d) 1/2
13. 13.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
14. 14.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/4 (c) 3/4 (d) 1/2
15. 15.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
16. 16.A bag has 8 white, 4 blue and 4 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/4 (b) 3/4 (c) 1/3 (d) 5/16
17. 17.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/4 (b) 1/3 (c) 5/6 (d) 2/3
18. 18.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
19. 19.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
20. 20.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
21. 21.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
22. 22.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/6 (b) 1/2 (c) 2/3 (d) 1/3
23. 23.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/5 (b) 5/6 (c) 1/6 (d) 1/3
24. 24.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/11 (b) 1/6 (c) 7/36 (d) 6/11
25. 25.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
26. 26.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 3/8 (c) 7/8 (d) 1/8
27. 27.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
28. 28.A bag has 5 green, 4 red and 5 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 9/14 (b) 5/14 (c) 5/9 (d) 1/3
29. 29.A bag has 7 red, 8 blue and 8 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 16/23 (b) 1/3 (c) 8/23 (d) 15/23
30. 30.A bag has 9 green, 4 blue and 4 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 13/17 (c) 4/17 (d) 14/17
31. 31.A bag has 8 red, 6 white and 8 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 4/11 (b) 7/11 (c) 4/7 (d) 1/3
32. 32.A bag has 2 yellow, 6 white and 3 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 7/11 (b) 6/11 (c) 1/3 (d) 5/11
33. 33.A bag has 6 blue, 5 red and 9 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/4 (b) 1/3 (c) 4/5 (d) 1/4
34. 34.A bag has 7 red, 5 yellow and 6 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 2/3 (b) 1/3 (c) 11/18 (d) 7/18
35. 35.A bag has 6 green, 8 blue and 2 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/8 (b) 1/3 (c) 1/7 (d) 7/8
36. 36.A bag has 9 red, 7 white and 5 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 5/7 (b) 1/21 (c) 2/3 (d) 1/3
37. 37.A bag has 5 red, 4 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 2/3 (b) 1/12 (c) 1/3 (d) 3/4
38. 38.A bag has 9 blue, 2 white and 5 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/16 (b) 1/3 (c) 5/11 (d) 11/16
39. 39.A bag has 8 white, 6 red and 4 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 2/3 (b) 1/3 (c) 1/18 (d) 13/18
40. 40.A bag has 2 white, 6 yellow and 2 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 4/5 (b) 1/5 (c) 1/4 (d) 1/3

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