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Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 510 · 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) 2/3 (b) 1/3 (c) 1/6 (d) 1/2
  2. 2.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
  3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/11 (b) 5/36 (c) 1/9 (d) 4/11
  4. 4.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 2/3 (b) 5/6 (c) 1/4 (d) 1/3
  5. 5.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 2/3 (c) 1/4 (d) 1/2
  6. 6.A bag has 3 red, 6 green and 6 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/5 (b) 13/15 (c) 1/3 (d) 4/5
  7. 7.A bag has 5 white, 8 red and 3 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 3/13 (c) 13/16 (d) 3/16
  8. 8.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/18 (b) 1/11 (c) 2/11 (d) 1/12
  9. 9.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 1/9 (c) 3/11 (d) 1/11
  10. 10.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
  11. 11.A bag has 2 white, 4 yellow and 7 red balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/3 (b) 9/13 (c) 4/13 (d) 4/9
  12. 12.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/6
  13. 13.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/8 (b) 3/8 (c) 1/4 (d) 7/8
  14. 14.A bag has 5 blue, 3 white and 2 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 9/10 (c) 1/5 (d) 4/5
  15. 15.Two coins are tossed together. What is the probability of getting at least one head? (a) 3/4 (b) 1/4 (c) 1/2 (d) 1/3
  16. 16.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/2 (b) 1/3 (c) 1/4 (d) 3/4
  17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/36 (b) 1/11 (c) 1/6 (d) 5/11
  18. 18.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 5/36 (c) 1/11 (d) 1/6
  19. 19.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 2/3 (b) 1/2 (c) 1/4 (d) 1/3
  20. 20.A bag has 8 red, 8 white and 8 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/2 (b) 2/3 (c) 1/3 (d) 3/8
  21. 21.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/6 (b) 1/3 (c) 1/2 (d) 2/3
  22. 22.A bag has 6 green, 2 white and 9 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 2/15 (c) 15/17 (d) 2/17
  23. 23.A bag has 6 red, 6 yellow and 3 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 1/4 (c) 1/5 (d) 4/5
  24. 24.A bag has 6 yellow, 3 red and 4 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/13 (b) 3/10 (c) 1/3 (d) 10/13
  25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 4/11 (b) 1/11 (c) 5/36 (d) 1/9
  26. 26.A bag has 5 white, 6 green and 6 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/3 (b) 6/17 (c) 11/17 (d) 6/11
  27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/11 (b) 6/11 (c) 7/36 (d) 1/6
  28. 28.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
  29. 29.A bag has 3 yellow, 9 white and 6 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/18 (b) 2/3 (c) 1/3 (d) 13/18
  30. 30.A bag has 3 green, 3 white and 7 blue balls. One ball is taken out without looking. What is the probability that it is not white? (a) 3/13 (b) 11/13 (c) 1/3 (d) 10/13
  31. 31.A bag has 3 yellow, 4 red and 3 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/5 (b) 2/3 (c) 2/5 (d) 1/3
  32. 32.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
  33. 33.A bag has 2 yellow, 8 white and 2 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 5/6 (b) 1/6 (c) 1/3 (d) 11/12
  34. 34.A bag has 3 yellow, 4 green and 3 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 3/10 (b) 3/7 (c) 1/3 (d) 7/10
  35. 35.A bag has 2 white, 2 yellow and 3 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 2/7 (b) 5/7 (c) 1/3 (d) 6/7
  36. 36.A bag has 6 green, 3 red and 6 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 2/3 (b) 1/3 (c) 3/5 (d) 2/5
  37. 37.A bag has 6 yellow, 8 white and 6 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 13/20 (b) 1/3 (c) 3/5 (d) 2/5
  38. 38.A bag has 2 green, 4 white and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/5 (b) 1/3 (c) 4/5 (d) 9/10
  39. 39.Three coins are tossed together. What is the probability of getting exactly one head? (a) 5/8 (b) 3/8 (c) 1/4 (d) 3/5
  40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/12 (c) 1/36 (d) 1/11

Answer key

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

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