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Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 585 · 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 dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/12 (b) 1/11 (c) 2/11 (d) 1/18
  2. 2.A bag has 3 blue, 3 white and 2 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 3/5 (b) 5/8 (c) 1/3 (d) 3/8
  3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/12 (b) 3/11 (c) 1/9 (d) 1/11
  4. 4.A fair dice is rolled once. What is the probability of getting an odd number? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
  5. 5.A bag has 2 white, 8 green and 9 blue balls. One ball is taken out without looking. What is the probability that it is not white? (a) 18/19 (b) 2/19 (c) 17/19 (d) 1/3
  6. 6.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 2/3 (c) 1/2 (d) 1/3
  7. 7.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
  8. 8.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
  9. 9.A bag has 5 yellow, 7 blue and 3 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 2/3 (c) 11/15 (d) 1/15
  10. 10.A bag has 3 green, 3 red and 5 blue balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/11 (b) 6/11 (c) 5/6 (d) 1/3
  11. 11.A bag has 2 blue, 9 green and 4 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 4/15 (b) 4/5 (c) 11/15 (d) 1/3
  12. 12.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 1/3 (c) 2/3 (d) 1/4
  13. 13.A bag has 5 blue, 5 red and 8 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/18 (b) 5/13 (c) 13/18 (d) 1/3
  14. 14.A bag has 4 yellow, 9 blue and 7 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/20 (b) 7/13 (c) 1/3 (d) 13/20
  15. 15.A bag has 3 green, 7 red and 6 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 9/16 (b) 7/16 (c) 7/9 (d) 1/3
  16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 1/11 (b) 5/36 (c) 5/11 (d) 1/6
  17. 17.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
  18. 18.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 1/11 (c) 6/11 (d) 7/36
  19. 19.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 4/11 (b) 5/36 (c) 1/11 (d) 1/9
  20. 20.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/3 (b) 3/4 (c) 1/4 (d) 1/2
  21. 21.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/3 (b) 1/4 (c) 2/3 (d) 1/2
  22. 22.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 5/6 (b) 1/3 (c) 1/6 (d) 1/5
  23. 23.A bag has 3 yellow, 2 blue and 4 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/9 (b) 1/3 (c) 7/9 (d) 2/3
  24. 24.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/4 (b) 1/8 (c) 1/4 (d) 3/8
  25. 25.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
  26. 26.A bag has 2 red, 7 white and 4 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 6/13 (b) 7/13 (c) 6/7 (d) 1/3
  27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/36 (c) 1/11 (d) 1/12
  28. 28.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 1/4 (c) 5/8 (d) 3/5
  29. 29.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 3/4 (b) 1/3 (c) 1/2 (d) 1/4
  30. 30.Three coins are tossed together. What is the probability of getting at least one head? (a) 7/8 (b) 1/4 (c) 3/8 (d) 1/8
  31. 31.A bag has 6 green, 7 white and 6 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 12/19 (c) 7/19 (d) 7/12
  32. 32.A bag has 9 blue, 8 red and 6 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 8/15 (c) 15/23 (d) 8/23
  33. 33.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 2/3 (c) 1/3 (d) 1/2
  34. 34.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/8 (b) 1/7 (c) 1/4 (d) 7/8
  35. 35.A bag has 9 green, 3 white and 3 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 13/15 (b) 1/5 (c) 1/3 (d) 4/5
  36. 36.A bag has 9 green, 3 white and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 7/9 (b) 1/3 (c) 7/16 (d) 9/16
  37. 37.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/6 (b) 1/3 (c) 2/3 (d) 1/2
  38. 38.A bag has 6 white, 6 blue and 8 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 2/3 (b) 1/3 (c) 3/5 (d) 2/5
  39. 39.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/36 (c) 1/12 (d) 1/18
  40. 40.A bag has 2 blue, 3 yellow and 7 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 1/4 (c) 5/6 (d) 3/4

Answer key

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

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