Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 98 · 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 factor of 6? (a) 1/4 (b) 2/3 (c) 5/6 (d) 1/3
2. 2.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
3. 3.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
4. 4.A bag has 4 red, 3 green and 5 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 2/3 (b) 5/12 (c) 7/12 (d) 1/3
5. 5.A bag has 2 white, 3 blue and 3 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 3/8 (c) 3/5 (d) 5/8
6. 6.A bag has 8 green, 3 red and 5 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 9/16 (b) 1/16 (c) 1/2 (d) 1/3
7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/6 (b) 5/36 (c) 5/11 (d) 1/11
8. 8.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 5/6 (b) 1/3 (c) 2/3 (d) 1/4
9. 9.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
10. 10.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 5/8 (c) 1/4 (d) 3/8
11. 11.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 2/11 (c) 1/12 (d) 1/18
12. 12.A bag has 4 red, 3 white and 7 blue balls. One ball is taken out without looking. What is the probability that it is not red? (a) 5/7 (b) 1/3 (c) 11/14 (d) 2/7
13. 13.A bag has 6 green, 2 blue and 3 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/11 (b) 1/3 (c) 8/11 (d) 3/8
14. 14.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 2/3 (c) 1/4 (d) 1/3
15. 15.A bag has 2 white, 7 yellow and 4 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 9/13 (c) 10/13 (d) 4/13
16. 16.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/3 (b) 1/2 (c) 1/4 (d) 2/3
17. 17.A bag has 6 white, 7 blue and 7 red balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 13/20 (b) 1/3 (c) 7/10 (d) 7/20
18. 18.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 3/4 (c) 1/4 (d) 1/2
19. 19.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/8 (c) 1/4 (d) 1/7
20. 20.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
21. 21.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 1/8 (c) 3/4 (d) 3/8
22. 22.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/2 (b) 1/3 (c) 1/6 (d) 2/3
23. 23.A bag has 2 white, 7 blue and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 10/13 (b) 1/3 (c) 9/13 (d) 4/13
24. 24.A bag has 9 green, 5 blue and 7 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 5/16 (c) 16/21 (d) 5/21
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/6 (b) 1/11 (c) 5/11 (d) 5/36
26. 26.A bag has 4 red, 6 yellow and 7 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 7/10 (b) 10/17 (c) 7/17 (d) 1/3
27. 27.A bag has 4 green, 9 red and 2 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 13/15 (c) 2/15 (d) 2/13
28. 28.A bag has 7 yellow, 6 blue and 9 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 8/11 (b) 3/8 (c) 1/3 (d) 3/11
29. 29.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
30. 30.A bag has 5 green, 7 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/4 (b) 3/7 (c) 4/7 (d) 1/3
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/36 (b) 1/11 (c) 1/18 (d) 1/12
32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/11 (b) 1/9 (c) 5/36 (d) 4/11
33. 33.A bag has 5 green, 7 yellow and 9 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 16/21 (b) 5/21 (c) 5/16 (d) 1/3
34. 34.A bag has 6 blue, 9 yellow and 6 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/5 (b) 2/7 (c) 1/3 (d) 5/7
35. 35.A bag has 6 yellow, 8 red and 3 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 3/17 (b) 14/17 (c) 1/3 (d) 3/14
36. 36.A bag has 5 blue, 4 white and 2 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 5/11 (c) 5/6 (d) 6/11
37. 37.A bag has 4 yellow, 6 green and 8 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 2/9 (b) 1/3 (c) 7/9 (d) 2/7
38. 38.A bag has 2 blue, 6 yellow and 4 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 1/12 (c) 7/12 (d) 1/2
39. 39.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 7/36 (c) 1/11 (d) 6/11

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