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Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 577 · 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, 7 blue and 8 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/8 (b) 2/3 (c) 5/8 (d) 1/3
  2. 2.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 3/8 (c) 7/8 (d) 1/8
  3. 3.A bag has 6 white, 4 green and 2 blue balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/2 (b) 1/12 (c) 1/3 (d) 7/12
  4. 4.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/8 (c) 3/5 (d) 5/8
  5. 5.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
  6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 1/12 (c) 1/18 (d) 2/11
  7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/11 (b) 1/36 (c) 1/18 (d) 1/12
  8. 8.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
  9. 9.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 5/11 (b) 1/11 (c) 5/36 (d) 1/6
  10. 10.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
  11. 11.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/6 (b) 1/2 (c) 1/3 (d) 2/3
  12. 12.A bag has 8 green, 8 yellow and 2 white balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 5/9 (c) 4/9 (d) 11/18
  13. 13.A bag has 6 white, 9 yellow and 4 green balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 9/10 (b) 9/19 (c) 1/3 (d) 10/19
  14. 14.A bag has 2 red, 3 white and 8 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 2/11 (b) 11/13 (c) 2/13 (d) 1/3
  15. 15.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/4 (b) 1/4 (c) 1/8 (d) 3/8
  16. 16.A bag has 9 white, 3 green and 3 red balls. One ball is taken out without looking. What is the probability that it is white? (a) 2/5 (b) 3/5 (c) 2/3 (d) 1/3
  17. 17.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/12 (c) 1/36 (d) 1/18
  18. 18.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/2 (b) 2/3 (c) 1/4 (d) 1/3
  19. 19.A bag has 3 green, 5 white and 6 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 11/14 (b) 3/14 (c) 3/11 (d) 1/3
  20. 20.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 2/3 (c) 1/4 (d) 1/3
  21. 21.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 7/36 (b) 1/6 (c) 1/11 (d) 6/11
  22. 22.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/2 (b) 2/3 (c) 1/3 (d) 1/4
  23. 23.A bag has 8 blue, 2 yellow and 6 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/2 (b) 1/3 (c) 1/16 (d) 9/16
  24. 24.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/4 (b) 1/7 (c) 7/8 (d) 1/8
  25. 25.A bag has 3 green, 3 blue and 4 white balls. One ball is taken out without looking. What is the probability that it is green? (a) 3/7 (b) 7/10 (c) 3/10 (d) 1/3
  26. 26.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/3 (b) 1/6 (c) 5/6 (d) 1/5
  27. 27.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
  28. 28.A bag has 3 green, 4 blue and 3 yellow balls. One ball is taken out without looking. What is the probability that it is blue? (a) 2/5 (b) 1/3 (c) 3/5 (d) 2/3
  29. 29.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 3/11 (c) 1/11 (d) 1/9
  30. 30.A bag has 6 white, 3 green 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) 1/3 (d) 7/12
  31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/11 (b) 5/36 (c) 1/9 (d) 4/11
  32. 32.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 1/4 (c) 1/3 (d) 3/4
  33. 33.A fair dice is rolled once. What is the probability of getting a number greater than 3? (a) 2/3 (b) 1/6 (c) 1/3 (d) 1/2
  34. 34.A bag has 3 yellow, 5 white and 9 red balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 3/17 (b) 1/3 (c) 15/17 (d) 14/17
  35. 35.A bag has 5 green, 2 red and 8 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 1/3 (b) 8/15 (c) 7/8 (d) 7/15
  36. 36.A bag has 6 yellow, 2 red and 7 green balls. One ball is taken out without looking. What is the probability that it is not red? (a) 2/15 (b) 14/15 (c) 1/3 (d) 13/15
  37. 37.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 2/11 (b) 1/11 (c) 1/12 (d) 1/18
  38. 38.A bag has 9 blue, 9 red and 3 white balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 3/7 (b) 4/7 (c) 1/3 (d) 13/21
  39. 39.A bag has 6 red, 3 green and 5 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 5/14 (b) 1/3 (c) 5/7 (d) 9/14
  40. 40.A bag has 2 yellow, 7 red and 2 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 8/11 (b) 4/11 (c) 7/11 (d) 1/3

Answer key

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

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