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Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 521 · 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 fair dice is rolled once. What is the probability of getting a prime number? (a) 1/2 (b) 1/6 (c) 2/3 (d) 1/3
  2. 2.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 2/3 (b) 1/3 (c) 1/4 (d) 1/2
  3. 3.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
  4. 4.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/12 (b) 1/11 (c) 1/9 (d) 3/11
  5. 5.A bag has 2 green, 3 white and 2 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 6/7 (b) 5/7 (c) 2/7 (d) 1/3
  6. 6.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
  7. 7.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/8 (c) 1/7 (d) 7/8
  8. 8.A bag has 6 red, 8 white and 6 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/10 (b) 1/3 (c) 7/10 (d) 3/4
  9. 9.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 7/8 (c) 1/8 (d) 3/8
  10. 10.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 1/6 (c) 1/11 (d) 5/36
  11. 11.A bag has 2 green, 6 blue and 8 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/7 (b) 1/8 (c) 7/8 (d) 1/3
  12. 12.A bag has 3 yellow, 9 blue and 9 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 1/7 (c) 6/7 (d) 19/21
  13. 13.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/12 (b) 1/18 (c) 1/11 (d) 2/11
  14. 14.A bag has 8 red, 6 green and 2 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 15/16 (b) 7/8 (c) 1/8 (d) 1/3
  15. 15.A bag has 4 red, 3 green and 3 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 7/10 (b) 3/7 (c) 1/3 (d) 3/10
  16. 16.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/3 (c) 1/2 (d) 1/6
  17. 17.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 3/8 (c) 1/4 (d) 5/8
  18. 18.A bag has 9 blue, 7 red and 5 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 5/21 (b) 17/21 (c) 16/21 (d) 1/3
  19. 19.A bag has 7 white, 6 blue and 4 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 10/17 (b) 7/17 (c) 7/10 (d) 1/3
  20. 20.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
  21. 21.A bag has 5 green, 7 red and 4 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/4 (b) 1/3 (c) 3/4 (d) 5/16
  22. 22.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/5 (b) 1/6 (c) 1/3 (d) 5/6
  23. 23.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
  24. 24.A bag has 5 blue, 3 red and 7 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 11/15 (b) 1/15 (c) 2/3 (d) 1/3
  25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/11 (b) 1/11 (c) 5/36 (d) 1/6
  26. 26.A bag has 6 blue, 6 white and 7 yellow balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 13/19 (b) 1/3 (c) 6/19 (d) 14/19
  27. 27.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
  28. 28.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/9 (b) 1/11 (c) 1/12 (d) 3/11
  29. 29.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/8 (b) 3/4 (c) 1/4 (d) 3/8
  30. 30.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/18 (b) 1/12 (c) 1/11 (d) 2/11
  31. 31.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 1/3 (c) 2/3 (d) 1/4
  32. 32.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/36 (b) 1/12 (c) 1/18 (d) 1/11
  33. 33.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/6
  34. 34.A bag has 3 white, 2 green and 3 blue balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 3/8 (c) 1/4 (d) 3/4
  35. 35.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
  36. 36.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
  37. 37.A bag has 6 yellow, 6 red and 5 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 13/17 (c) 12/17 (d) 5/17
  38. 38.A bag has 4 green, 6 red and 6 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 3/4 (c) 1/4 (d) 5/16
  39. 39.A bag has 2 red, 2 yellow and 5 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 4/9 (b) 5/9 (c) 1/3 (d) 2/3
  40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/9 (b) 5/36 (c) 4/11 (d) 1/11

Answer key

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

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