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Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 147 · 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 yellow, 5 green and 3 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 12/17 (b) 5/17 (c) 1/3 (d) 5/12
  2. 2.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
  3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/18 (b) 2/11 (c) 1/11 (d) 1/12
  4. 4.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/3 (b) 1/2 (c) 2/3 (d) 1/6
  5. 5.A bag has 3 green, 6 red and 5 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 5/14 (b) 1/3 (c) 5/7 (d) 9/14
  6. 6.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/6 (c) 1/2 (d) 1/3
  7. 7.A bag has 2 blue, 5 red and 2 green balls. One ball is taken out without looking. What is the probability that it is not green? (a) 1/3 (b) 7/9 (c) 8/9 (d) 2/9
  8. 8.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
  9. 9.A bag has 6 white, 3 blue and 5 green balls. One ball is taken out without looking. What is the probability that it is not white? (a) 3/7 (b) 4/7 (c) 1/3 (d) 9/14
  10. 10.A bag has 5 yellow, 4 white and 6 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 11/15 (c) 4/15 (d) 4/11
  11. 11.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
  12. 12.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
  13. 13.A fair dice is rolled once. What is the probability of getting a number greater than 4? (a) 1/3 (b) 1/2 (c) 1/6 (d) 2/3
  14. 14.A bag has 5 green, 4 yellow and 4 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 9/13 (b) 1/3 (c) 4/9 (d) 4/13
  15. 15.A bag has 7 white, 2 yellow and 5 blue balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 1/2 (c) 4/7 (d) 1/14
  16. 16.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/12 (b) 1/18 (c) 1/36 (d) 1/11
  17. 17.A fair dice is rolled once. What is the probability of getting a number greater than 1? (a) 1/3 (b) 1/6 (c) 1/5 (d) 5/6
  18. 18.A bag has 3 yellow, 6 green and 9 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 5/6 (b) 1/3 (c) 1/6 (d) 1/5
  19. 19.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 1/9 (b) 4/11 (c) 5/36 (d) 1/11
  20. 20.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 1/4 (c) 3/5 (d) 5/8
  21. 21.A bag has 5 blue, 5 red and 4 green balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 9/14 (b) 1/3 (c) 5/7 (d) 5/14
  22. 22.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
  23. 23.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 7/8 (b) 1/4 (c) 1/8 (d) 1/7
  24. 24.A bag has 3 white, 5 green and 4 yellow balls. One ball is taken out without looking. What is the probability that it is not white? (a) 3/4 (b) 1/4 (c) 5/6 (d) 1/3
  25. 25.A bag has 5 blue, 4 yellow and 9 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/3 (b) 5/9 (c) 1/18 (d) 1/2
  26. 26.A bag has 9 yellow, 2 blue and 5 white balls. One ball is taken out without looking. What is the probability that it is blue? (a) 1/3 (b) 7/8 (c) 1/7 (d) 1/8
  27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/9 (b) 3/11 (c) 1/12 (d) 1/11
  28. 28.A bag has 6 yellow, 2 blue and 5 green balls. One ball is taken out without looking. What is the probability that it is blue? (a) 11/13 (b) 1/3 (c) 2/13 (d) 2/11
  29. 29.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 1/3 (b) 5/6 (c) 2/3 (d) 1/4
  30. 30.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/12 (b) 1/11 (c) 3/11 (d) 1/9
  31. 31.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
  32. 32.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/2 (b) 1/4 (c) 3/4 (d) 1/3
  33. 33.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 2/3 (c) 1/2 (d) 1/3
  34. 34.A bag has 3 white, 9 green and 7 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 9/10 (b) 10/19 (c) 9/19 (d) 1/3
  35. 35.A bag has 5 red, 2 green and 5 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 5/12 (b) 5/7 (c) 7/12 (d) 1/3
  36. 36.A bag has 7 red, 2 white and 6 yellow balls. One ball is taken out without looking. What is the probability that it is not red? (a) 3/5 (b) 8/15 (c) 1/3 (d) 7/15
  37. 37.A bag has 5 white, 9 blue and 7 yellow balls. One ball is taken out without looking. What is the probability that it is white? (a) 1/3 (b) 5/21 (c) 5/16 (d) 16/21
  38. 38.A bag has 3 yellow, 5 red and 6 blue balls. One ball is taken out without looking. What is the probability that it is red? (a) 9/14 (b) 1/3 (c) 5/9 (d) 5/14
  39. 39.A bag has 2 blue, 7 yellow and 6 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 7/8 (b) 8/15 (c) 7/15 (d) 1/3
  40. 40.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2

Answer key

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

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