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Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 95 · 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.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
  2. 2.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
  3. 3.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
  4. 4.A bag has 8 green, 4 yellow and 9 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 17/21 (c) 4/21 (d) 6/7
  5. 5.A bag has 5 blue, 7 white and 4 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 5/16 (c) 11/16 (d) 5/11
  6. 6.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
  7. 7.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/4 (b) 5/6 (c) 2/3 (d) 1/3
  8. 8.A bag has 3 red, 5 green and 7 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/15 (b) 2/3 (c) 11/15 (d) 1/3
  9. 9.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/8 (b) 3/4 (c) 1/8 (d) 1/4
  10. 10.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/11 (c) 1/12 (d) 1/9
  11. 11.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/3 (b) 1/6 (c) 1/2 (d) 2/3
  12. 12.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/3 (b) 1/2 (c) 3/4 (d) 1/4
  13. 13.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 7/8 (c) 1/7 (d) 1/8
  14. 14.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
  15. 15.A bag has 4 green, 4 red and 9 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 13/17 (b) 4/17 (c) 4/13 (d) 1/3
  16. 16.A bag has 9 red, 7 yellow and 6 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 9/22 (c) 13/22 (d) 9/13
  17. 17.A bag has 5 blue, 6 red and 2 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 12/13 (c) 2/13 (d) 11/13
  18. 18.A bag has 6 white, 2 yellow and 9 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 8/9 (b) 8/17 (c) 9/17 (d) 1/3
  19. 19.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 5/6 (b) 1/3 (c) 1/4 (d) 2/3
  20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/11 (b) 5/36 (c) 1/11 (d) 1/6
  21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/11 (b) 7/36 (c) 1/6 (d) 6/11
  22. 22.A bag has 6 blue, 8 white and 7 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/7 (b) 5/7 (c) 2/5 (d) 1/3
  23. 23.A bag has 3 yellow, 2 green and 8 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 11/13 (b) 1/3 (c) 3/13 (d) 10/13
  24. 24.A bag has 3 green, 8 red and 8 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 16/19 (b) 3/16 (c) 3/19 (d) 1/3
  25. 25.A bag has 5 green, 5 white and 9 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 9/19 (c) 9/10 (d) 10/19
  26. 26.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
  27. 27.A bag has 8 yellow, 7 blue and 4 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 12/19 (b) 1/3 (c) 11/19 (d) 8/19
  28. 28.A bag has 9 green, 3 red and 7 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 10/19 (c) 9/19 (d) 9/10
  29. 29.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/6
  30. 30.Two coins are tossed together. What is the probability of getting exactly one head? (a) 2/3 (b) 1/2 (c) 1/4 (d) 1/3
  31. 31.A bag has 5 green, 8 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 16/21 (b) 17/21 (c) 1/3 (d) 5/21
  32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/11 (b) 3/11 (c) 1/9 (d) 1/12
  33. 33.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
  34. 34.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
  35. 35.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/12 (b) 1/18 (c) 1/36 (d) 1/11
  36. 36.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 1/2 (b) 2/3 (c) 1/6 (d) 1/3
  37. 37.A bag has 5 white, 7 red and 9 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 17/21 (b) 16/21 (c) 5/21 (d) 1/3
  38. 38.A bag has 3 blue, 2 red and 7 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 5/7 (b) 7/12 (c) 5/12 (d) 1/3
  39. 39.A bag has 3 green, 4 blue and 3 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 3/7 (c) 7/10 (d) 3/10
  40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 4/11 (b) 1/9 (c) 1/11 (d) 5/36

Answer key

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

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