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Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 69 · 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 factor of 6? (a) 1/4 (b) 5/6 (c) 1/3 (d) 2/3
  2. 2.A bag has 8 blue, 6 red and 6 white balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/10 (b) 3/4 (c) 1/3 (d) 7/10
  3. 3.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/2 (c) 1/4 (d) 3/4
  4. 4.A bag has 5 yellow, 3 blue and 9 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 10/17 (b) 9/17 (c) 1/3 (d) 8/17
  5. 5.A bag has 7 red, 3 yellow and 3 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 8/13 (b) 7/13 (c) 1/3 (d) 6/13
  6. 6.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/11 (b) 1/18 (c) 1/36 (d) 1/12
  7. 7.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 7/36 (b) 6/11 (c) 1/11 (d) 1/6
  8. 8.A bag has 9 red, 7 green and 3 yellow balls. One ball is taken out without looking. What is the probability that it is red? (a) 9/10 (b) 10/19 (c) 9/19 (d) 1/3
  9. 9.A bag has 7 red, 9 green and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 17/21 (c) 5/21 (d) 16/21
  10. 10.Two coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 1/2 (c) 2/3 (d) 1/3
  11. 11.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/2 (b) 1/3 (c) 1/4 (d) 3/4
  12. 12.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 5/36 (b) 4/11 (c) 1/9 (d) 1/11
  13. 13.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
  14. 14.A bag has 9 blue, 7 red and 6 white balls. One ball is taken out without looking. What is the probability that it is red? (a) 7/15 (b) 7/22 (c) 1/3 (d) 15/22
  15. 15.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/3 (b) 1/6 (c) 2/3 (d) 1/2
  16. 16.Three coins are tossed together. What is the probability of getting exactly one head? (a) 1/4 (b) 3/5 (c) 3/8 (d) 5/8
  17. 17.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
  18. 18.Three coins are tossed together. What is the probability of getting at least one head? (a) 1/4 (b) 3/8 (c) 1/8 (d) 7/8
  19. 19.A bag has 8 blue, 7 yellow and 8 red balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 8/15 (c) 8/23 (d) 15/23
  20. 20.A bag has 3 red, 2 green and 4 white balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 4/9 (c) 5/9 (d) 4/5
  21. 21.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 2/3 (c) 1/2 (d) 1/6
  22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/18 (b) 1/12 (c) 1/36 (d) 1/11
  23. 23.A bag has 9 white, 8 green and 7 yellow balls. One ball is taken out without looking. What is the probability that it is green? (a) 1/3 (b) 2/3 (c) 3/8 (d) 1/2
  24. 24.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/6 (b) 5/6 (c) 1/5 (d) 1/3
  25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 1/11 (b) 1/18 (c) 1/12 (d) 2/11
  26. 26.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 2/3 (b) 1/3 (c) 5/6 (d) 1/4
  27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 4/11 (b) 5/36 (c) 1/11 (d) 1/9
  28. 28.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
  29. 29.A bag has 5 yellow, 5 green and 2 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 5/6 (b) 11/12 (c) 1/3 (d) 1/6
  30. 30.Two dice are rolled together. What is the probability that the two numbers add up to 6? (a) 1/6 (b) 1/11 (c) 5/36 (d) 5/11
  31. 31.A bag has 2 green, 7 yellow and 3 red balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/6 (b) 11/12 (c) 1/3 (d) 5/6
  32. 32.A bag has 2 red, 4 yellow and 8 green balls. One ball is taken out without looking. What is the probability that it is red? (a) 1/6 (b) 1/3 (c) 6/7 (d) 1/7
  33. 33.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
  34. 34.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
  35. 35.A bag has 3 red, 3 green and 7 yellow balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 10/13 (c) 11/13 (d) 3/13
  36. 36.A bag has 3 red, 4 green and 2 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 8/9 (b) 2/9 (c) 7/9 (d) 1/3
  37. 37.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 2/3 (b) 1/2 (c) 1/6 (d) 1/3
  38. 38.A bag has 3 blue, 2 green and 3 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 5/8 (b) 3/8 (c) 1/3 (d) 3/5
  39. 39.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/6 (b) 5/6 (c) 1/5 (d) 1/3
  40. 40.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 3/11 (b) 1/11 (c) 1/9 (d) 1/12

Answer key

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

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