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Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 122 · 40 questions
TalentJR

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.

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

Answer key

  1. 1/3
  2. 1/2
  3. 1/8
  4. 2/3
  5. 5/14
  6. 3/4
  7. 1/3
  8. 1/2
  9. 1/4
  10. 1/2
  11. 3/8
  12. 1/3
  13. 1/12
  14. 1/9
  15. 1/18
  16. 17/23
  17. 7/13
  18. 3/8
  19. 1/3
  20. 2/3
  21. 5/36
  22. 5/6
  23. 1/36
  24. 2/9
  25. 1/2
  26. 1/6
  27. 3/7
  28. 5/13
  29. 1/18
  30. 3/4
  31. 10/13
  32. 11/17
  33. 7/19
  34. 8/11
  35. 1/6
  36. 2/5
  37. 1/4
  38. 1/2
  39. 7/8
  40. 1/2

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