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Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 441 · 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 2 white, 8 green and 2 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 5/6 (b) 1/3 (c) 1/6 (d) 1/5
  2. 2.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
  3. 3.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
  4. 4.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
  5. 5.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/8 (b) 1/4 (c) 3/4 (d) 3/8
  6. 6.A fair dice is rolled once. What is the probability of getting a prime number? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
  7. 7.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
  8. 8.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/7 (c) 7/8 (d) 1/8
  9. 9.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
  10. 10.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 2/11 (c) 1/11 (d) 1/18
  11. 11.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) 2/3 (d) 1/4
  12. 12.A bag has 6 blue, 4 yellow and 8 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/2 (b) 1/3 (c) 7/18 (d) 2/3
  13. 13.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 1/3 (b) 2/3 (c) 5/6 (d) 1/4
  14. 14.Three coins are tossed together. What is the probability of getting exactly one head? (a) 5/8 (b) 1/4 (c) 3/5 (d) 3/8
  15. 15.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
  16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 7/36 (b) 1/6 (c) 6/11 (d) 1/11
  17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/12 (b) 1/18 (c) 1/36 (d) 1/11
  18. 18.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/4
  19. 19.A bag has 7 yellow, 6 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 7/22 (b) 1/3 (c) 15/22 (d) 8/11
  20. 20.A bag has 4 yellow, 5 red and 2 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 8/11 (b) 1/3 (c) 7/11 (d) 4/11
  21. 21.A bag has 2 blue, 2 yellow and 6 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/5 (b) 4/5 (c) 1/3 (d) 9/10
  22. 22.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/2 (b) 1/6 (c) 2/3 (d) 1/3
  23. 23.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
  24. 24.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 1/2 (c) 3/4 (d) 1/3
  25. 25.A bag has 2 white, 8 red and 7 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/17 (b) 1/3 (c) 10/17 (d) 7/10
  26. 26.A fair dice is rolled once. What is the probability of getting a number less than 5? (a) 1/4 (b) 1/3 (c) 5/6 (d) 2/3
  27. 27.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
  28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/11 (b) 5/36 (c) 1/6 (d) 5/11
  29. 29.A bag has 2 green, 4 white and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 13/14 (b) 6/7 (c) 1/3 (d) 1/7
  30. 30.A bag has 6 white, 2 green and 6 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 6/7 (b) 1/7 (c) 1/6 (d) 1/3
  31. 31.A bag has 3 red, 7 green and 3 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 6/13 (c) 7/13 (d) 8/13
  32. 32.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
  33. 33.A bag has 3 red, 3 yellow and 3 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 4/9 (b) 1/2 (c) 2/3 (d) 1/3
  34. 34.A bag has 8 yellow, 6 white and 7 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 13/21 (b) 8/21 (c) 8/13 (d) 1/3
  35. 35.A bag has 7 red, 7 green and 3 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 10/17 (c) 7/10 (d) 7/17
  36. 36.A bag has 5 yellow, 8 white and 3 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 3/16 (c) 13/16 (d) 3/13
  37. 37.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/6
  38. 38.A bag has 7 blue, 5 green and 8 red 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) 3/10
  39. 39.A bag has 2 blue, 7 white and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 2/17 (b) 15/17 (c) 16/17 (d) 1/3
  40. 40.A bag has 6 green, 2 red and 9 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 6/17 (b) 11/17 (c) 6/11 (d) 1/3

Answer key

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

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