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Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 307 · 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 9 red, 5 white and 3 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 14/17 (b) 15/17 (c) 1/3 (d) 3/17
  2. 2.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/7 (b) 1/8 (c) 7/8 (d) 1/4
  3. 3.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
  4. 4.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/9 (b) 1/11 (c) 5/36 (d) 4/11
  5. 5.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/4 (b) 5/6 (c) 1/3 (d) 2/3
  6. 6.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
  7. 7.A bag has 8 white, 9 yellow and 7 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 2/3 (b) 1/3 (c) 5/8 (d) 3/8
  8. 8.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
  9. 9.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 3/4 (c) 1/2 (d) 1/4
  10. 10.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/4
  11. 11.A bag has 7 yellow, 7 red and 8 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 7/11 (b) 1/3 (c) 4/7 (d) 4/11
  12. 12.A bag has 3 blue, 3 white and 5 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 3/11 (b) 3/8 (c) 1/3 (d) 8/11
  13. 13.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/5 (b) 1/4 (c) 3/8 (d) 5/8
  14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/36 (b) 1/18 (c) 1/12 (d) 1/11
  15. 15.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 3/4 (c) 1/4 (d) 1/3
  16. 16.Three coins are tossed together. What is the probability of getting at least one head? (a) 3/8 (b) 1/8 (c) 7/8 (d) 1/4
  17. 17.A bag has 3 blue, 6 white and 3 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/2 (b) 1/12 (c) 7/12 (d) 1/3
  18. 18.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 5/6 (b) 1/3 (c) 1/6 (d) 1/5
  19. 19.A bag has 3 red, 9 yellow and 3 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 4/5 (b) 13/15 (c) 1/3 (d) 1/5
  20. 20.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
  21. 21.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
  22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/12 (c) 1/9 (d) 1/11
  23. 23.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/2 (b) 1/4 (c) 2/3 (d) 1/3
  24. 24.A bag has 9 green, 8 red and 3 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 9/10 (c) 17/20 (d) 3/20
  25. 25.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/8 (b) 1/8 (c) 1/4 (d) 3/4
  26. 26.A fair dice is rolled once. What is the probability of getting an even number? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
  27. 27.A bag has 6 red, 9 yellow and 7 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 7/15 (b) 1/3 (c) 15/22 (d) 7/22
  28. 28.A bag has 9 white, 7 blue and 6 green balls. One ball is taken out without looking. What is the probability that it is white? (a) 13/22 (b) 1/3 (c) 9/13 (d) 9/22
  29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 1/6 (b) 1/11 (c) 7/36 (d) 6/11
  30. 30.A bag has 3 blue, 7 red and 2 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 1/4 (c) 5/6 (d) 3/4
  31. 31.A bag has 9 red, 3 green and 3 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 3/5 (b) 1/3 (c) 2/5 (d) 2/3
  32. 32.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
  33. 33.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/9 (b) 5/36 (c) 1/11 (d) 4/11
  34. 34.A bag has 3 red, 3 white and 6 yellow balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/2 (b) 7/12 (c) 1/12 (d) 1/3
  35. 35.A bag has 9 red, 4 blue and 8 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/7 (b) 1/3 (c) 13/21 (d) 4/7
  36. 36.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
  37. 37.A bag has 5 red, 3 yellow and 8 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 3/16 (b) 7/8 (c) 13/16 (d) 1/3
  38. 38.A bag has 9 blue, 5 red and 5 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 14/19 (b) 1/3 (c) 5/14 (d) 5/19
  39. 39.A bag has 7 yellow, 9 red and 8 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 5/8 (b) 3/8 (c) 1/3 (d) 2/3
  40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/12 (b) 1/36 (c) 1/18 (d) 1/11

Answer key

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

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