← Averages lesson New set →

Averages Worksheet for Maths Olympiad

Maths Olympiad topic 17: Averages · Set 428 · 40 questions
TalentJR

How to solve it (Think in totals): Average = total ÷ how many; so total = average × how many. A number taken away = old total − new total. Evenly spaced numbers (like 10 to 20): average = (first + last) ÷ 2.

NameDateTime takenScore ___ / 40
  1. 1.The average of 7 numbers is 25. When one number is taken away, the average of the rest is 29. Which number was taken away? (a) 54 (b) 1 (c) 25 (d) 2
  2. 2.The average of 4 numbers is 49. When one number is taken away, the average of the rest is 45. Which number was taken away? (a) 49 (b) 94 (c) 16 (d) 61
  3. 3.The average of 4 numbers is 45. When one number is taken away, the average of the rest is 43. Which number was taken away? (a) 45 (b) 8 (c) 88 (d) 51
  4. 4.The average of 5 numbers is 16. When one number is taken away, the average of the rest is 17. Which number was taken away? (a) 33 (b) 16 (c) 12 (d) 13
  5. 5.What is the average of all the whole numbers from 31 to 47? (a) 8 (b) 39 (c) 16 (d) 40
  6. 6.A batter has an average of 27 runs in 7 matches. How many runs are needed in the next match to raise the average to 29? (a) 43 (b) 16 (c) 29 (d) 31
  7. 7.The average of 7 numbers is 43. When one number is taken away, the average of the rest is 48. Which number was taken away? (a) 14 (b) 13 (c) 91 (d) 43
  8. 8.What is the average of 29, 38, 17, 36 and 5? (a) 27 (b) 25 (c) 24 (d) 26
  9. 9.The average of 7 numbers is 15. When one number is taken away, the average of the rest is 13. Which number was taken away? (a) 15 (b) 14 (c) 27 (d) 28
  10. 10.What is the average of all the whole numbers from 32 to 70? (a) 52 (b) 38 (c) 19 (d) 51
  11. 11.What is the average of all the whole numbers from 56 to 78? (a) 11 (b) 67 (c) 68 (d) 22
  12. 12.A batter has an average of 24 runs in 7 matches. How many runs are needed in the next match to raise the average to 30? (a) 30 (b) 48 (c) 36 (d) 72
  13. 13.What is the average of all the whole numbers from 44 to 64? (a) 20 (b) 10 (c) 55 (d) 54
  14. 14.The average of 4 numbers is 18. When one number is taken away, the average of the rest is 20. Which number was taken away? (a) 13 (b) 12 (c) 38 (d) 18
  15. 15.The average of 6 numbers is 28. When one number is taken away, the average of the rest is 23. Which number was taken away? (a) 53 (b) 30 (c) 51 (d) 28
  16. 16.A batter has an average of 43 runs in 4 matches. How many runs are needed in the next match to raise the average to 47? (a) 47 (b) 63 (c) 20 (d) 51
  17. 17.What is the average of 57, 66, 78, 56, 76 and 87? (a) 84 (b) 70 (c) 69 (d) 71
  18. 18.What is the average of 30, 52, 36, 27 and 45? (a) 40 (b) 38 (c) 37 (d) 39
  19. 19.What is the average of 61, 77, 68, 65 and 109? (a) 95 (b) 76 (c) 75 (d) 77
  20. 20.The average of 7 numbers is 35. When one number is taken away, the average of the rest is 39. Which number was taken away? (a) 74 (b) 12 (c) 35 (d) 11
  21. 21.A batter has an average of 41 runs in 3 matches. How many runs are needed in the next match to raise the average to 46? (a) 51 (b) 20 (c) 61 (d) 46
  22. 22.What is the average of all the whole numbers from 48 to 78? (a) 30 (b) 15 (c) 63 (d) 64
  23. 23.A batter has an average of 23 runs in 6 matches. How many runs are needed in the next match to raise the average to 31? (a) 79 (b) 56 (c) 31 (d) 39
  24. 24.The average of 8 numbers is 10. When one number is taken away, the average of the rest is 11. Which number was taken away? (a) 4 (b) 3 (c) 10 (d) 21
  25. 25.What is the average of 43, 58, 61, 55 and 43? (a) 65 (b) 53 (c) 51 (d) 52
  26. 26.The average of 4 numbers is 12. When one number is taken away, the average of the rest is 11. Which number was taken away? (a) 4 (b) 23 (c) 12 (d) 15
  27. 27.The average of 5 numbers is 30. When one number is taken away, the average of the rest is 25. Which number was taken away? (a) 25 (b) 30 (c) 55 (d) 50
  28. 28.A batter has an average of 28 runs in 5 matches. How many runs are needed in the next match to raise the average to 33? (a) 58 (b) 38 (c) 33 (d) 30
  29. 29.What is the average of 35, 56, 53, 54, 31 and 17? (a) 43 (b) 40 (c) 42 (d) 41
  30. 30.What is the average of 29, 36, 49, 28, 39 and 23? (a) 33 (b) 34 (c) 35 (d) 36
  31. 31.The average of 5 numbers is 29. When one number is taken away, the average of the rest is 34. Which number was taken away? (a) 63 (b) 29 (c) 10 (d) 9
  32. 32.A batter has an average of 24 runs in 3 matches. How many runs are needed in the next match to raise the average to 32? (a) 56 (b) 57 (c) 32 (d) 40
  33. 33.What is the average of all the whole numbers from 51 to 73? (a) 11 (b) 22 (c) 62 (d) 63
  34. 34.A batter has an average of 38 runs in 3 matches. How many runs are needed in the next match to raise the average to 41? (a) 50 (b) 12 (c) 44 (d) 41
  35. 35.A batter has an average of 42 runs in 7 matches. How many runs are needed in the next match to raise the average to 50? (a) 58 (b) 106 (c) 50 (d) 64
  36. 36.The average of 7 numbers is 37. When one number is taken away, the average of the rest is 41. Which number was taken away? (a) 37 (b) 13 (c) 14 (d) 78
  37. 37.The average of 4 numbers is 21. When one number is taken away, the average of the rest is 23. Which number was taken away? (a) 21 (b) 44 (c) 15 (d) 16
  38. 38.The average of 4 numbers is 39. When one number is taken away, the average of the rest is 41. Which number was taken away? (a) 39 (b) 80 (c) 34 (d) 33
  39. 39.What is the average of 32, 31, 15, 12, 12 and 36? (a) 24 (b) 23 (c) 22 (d) 25
  40. 40.The average of 5 numbers is 35. When one number is taken away, the average of the rest is 40. Which number was taken away? (a) 15 (b) 75 (c) 16 (d) 35

Answer key

  1. 1
  2. 61
  3. 51
  4. 12
  5. 39
  6. 43
  7. 13
  8. 25
  9. 27
  10. 51
  11. 67
  12. 72
  13. 54
  14. 12
  15. 53
  16. 63
  17. 70
  18. 38
  19. 76
  20. 11
  21. 61
  22. 63
  23. 79
  24. 3
  25. 52
  26. 15
  27. 50
  28. 58
  29. 41
  30. 34
  31. 9
  32. 56
  33. 62
  34. 50
  35. 106
  36. 13
  37. 15
  38. 33
  39. 23
  40. 15

Free maths olympiad lessons, practice and worksheets at talentjr.in/maths-olympiad