Average MCQ Questions and Answers in Quantitative Aptitude
1. 4 groups have sizes [6, 13, 21, 20] with averages [61, 110, 116, 48]. What is the overall average?
A. 82.53
B. 86.53
C. 87.53
D. 91.53
2. Two teams of sizes 8 and 10 have averages 37 and 22. Find overall average.
A. 30.67
B. 28.67
C. 34.67
D. 23.67
3. Two quantities of 97 and 52 units have values 22% and 2% respectively. What is the percentage of combined quantity?
A. 17.52
B. 15.02
C. 11.72
D. 18.40
4. A group of 12 numbers has an average of 69. If 4 numbers whose average is 41 are removed, what is the new average?
A. 61.50
B. 83.00
C. 64.00
D. 72.83
5. A group of 16 numbers has an average of 83. If 3 numbers whose average is 32 are removed, what is the new average?
A. 93.77
B. 91.27
C. 97.27
D. 94.77
6. For the arithmetic progression starting at 11 with common difference 2, the average of first 10 terms is?
A. 17.0
B. 24.0
C. 20.0
D. 19.0
7. Two classes have 13 and 28 students with average marks 81 and 74 respectively. What is the combined class average?
A. 76.22
B. 76.86
C. 75.86
D. 77.23
8. Average score of 9 tests is 72. A new test score 95 is added. New average becomes:
A. 74.3
B. 73.67
C. 75.67
D. 76.00
9. A set of 11 numbers has average 48. Replace a number 32 by x such that the new average becomes 51. Find x.
A. 70
B. 65
C. 94
D. 90
10. The combined average of three groups of sizes 7, 9, 14 are 84, 78, 92 respectively. What is the mean of all members?
A. 88.20
B. 85.93
C. 86.20
D. 87.50
11. Average of 15 values is 64. When two values 72 and 46 are removed, the average of remaining becomes 63. What was the sum of all 15 values?
A. 960
B. 965
C. 945
D. 972
12. There are 10 numbers whose average is 30. If each number is increased by 8, the new average is:
A. 38
B. 38
C. 32
D. 30
13. Average weight of 6 persons is 64 kg. If one person of weight 70 kg is replaced by a new person and new average becomes 63 kg, find the weight of the new person.
A. 64 kg
B. 55 kg
C. 58 kg
D. 50 kg
14. The average of 5 consecutive odd integers is 37. What is the smallest integer?
A. 33
B. 35
C. 33
D. 31
15. Ten numbers have an average of 50. Replacing two numbers 40 and 60 by 70 and x increases average by 1. Find x.
A. 59
B. 63
C. 62
D. 40
16. The average of first 20 natural numbers is:
A. 10.9
B. 10.5
C. 11
D. 9.5
17. Average of five numbers is 52. If one of the numbers is four times another, and the remaining three add to 120, find the numbers pair that satisfy average (one possible pair). (Consider integer solutions)
A. 28 & 112
B. 10 & 40
C. 12 & 48
D. 9 & 36
18. A class of 30 students has average marks 68. If 5 students leave and the average of remaining becomes 69, what is the average marks of the 5 who left?
A. 61
B. 57
C. 63
D. 65
19. If the average of x, y, z is 66 and x = 2y, z = y + 6, find y.
A. 48
B. 36
C. 30
D. 42
20. The average of 4 numbers is 26. If one number is tripled and another is halved while other two remain unchanged, the new average becomes 30. If the unchanged numbers are 24 and 20, find original values of modified numbers (order unknown) — choose the consistent answer.
A. 18 and 41.6
B. 12 and 40
C. 10 and 42
D. 14 and 36
21. Five students have average marks 76. If one student’s marks 84 is removed, average of remaining becomes 74. Find marks of the removed student (consistency check).
A. 86
B. 86
C. 84
D. 90
22. The average of 50 numbers is 200. If 25 of them have average 210, what is the average of remaining 25?
A. 190
B. 190
C. 180
D. 200
23. The average of 8 numbers is 45. If their average is increased by 4 after adding two new numbers, and the two new numbers are equal, find each of the two new numbers.
A. 65
B. 69
C. 63
D. 71
24. Averages of two samples of sizes 12 and 18 are 54 and 48 respectively. If combined sample average is A, then A equals:
A. 50.8
B. 51.2
C. 51.0
D. 50.4
25. The average height of 9 people is 170 cm. When a new person of height 186 cm joins, the average height becomes 171 cm. What is the height of the ninth person removed earlier? (Trick: find originally implied)
A. 180
B. 164
C. 168
D. 171
26. A set of 13 integers has average 40. If one value 28 is replaced by 64, new average is:
A. 42.77
B. 41.07
C. 40.28
D. 41
27. The arithmetic mean of three numbers is 64. If one number is twice the second and the third is 8 less than the second, find all three numbers.
A. 64, 32, 24
B. 72, 36, 28
C. 60, 30, 22
D. 100, 50, 42
28. For a dataset of 16 numbers whose average is 45, adding one number increases average by 1. The added number is:
A. 62
B. 61
C. 60
D. 63
29. The average of the first 50 positive even integers is:
A. 51
B. 51
C. 50
D. 52
30. The average of five positive numbers is 24. If four of them are in GP with ratio 2 and the fourth term is 16, find the fifth number.
A. 90
B. 28
C. 24
D. 32
31. The weighted average of 3 values 40, 50, 80 with weights 2, 3, 5 is:
A. 64
B. 65
C. 66
D. 63
32. A sequence of 9 consecutive integers has average 73. What is the range of the set (max – min)?
A. 8
B. 18
C. 16
D. 9
33. Two batches of batteries have average lifetimes 480 and 520 hours and sizes 65 and 35. The combined average is:
A. 498
B. 500
C. 494
D. 502
34. Average of 3 numbers is 88. If the first is 10 less than the second and the third is 4 more than the second, find the second number.
A. 86
B. 88
C. 90
D. 84
35. A teacher computes average of marks of 20 students as 72. Later realizes she mistakenly omitted 2 students who scored 88 and 76. New average becomes:
A. 73.2
B. 72.91
C. 73
D. 74
36. The average of 25 items is 36. If 5 items each of value 30 are removed, the average of the remaining becomes:
A. 37.5
B. 35.83
C. 38.33
D. 36.83
37. The average of 5 numbers is 40. If three of them are in AP: 34, 40, 46 and fourth is 55, find the fifth.
A. 25
B. 30
C. 35
D. 45
38. The average of first n odd numbers equals 50. n equals:
A. 100
B. 50
C. 49
D. 51
39. A class average is 78 for 40 students. If the top scorer with 100 is removed, the class average drops to 77.5. What is the sum of scores of the remaining class?
A. 31.00
B. 97.5
C. 3.100
D. 30.95
40. The mean of nine numbers is 33. After adding three numbers each equal to 47 the new mean becomes:
A. 37
B. 37
C. 36.5
D. 38
41. A list of 12 numbers has mean 50. If each number is multiplied by 2 and 6 is subtracted from each, the new mean is:
A. 94
B. 94
C. 100
D. 88
42. The average of 4 numbers is 39. If one number is doubled and another decreased by 6 while others unchanged, the new average becomes 42. If unchanged numbers are 40 and 38, find the original two numbers.
A. 34 and 42
B. 30 and 44
C. 32 and 46
D. 18 and 60
43. Nine numbers have average 52. If three numbers 46, 55, 59 are removed, new average is:
A. 54
B. 52.25
C. 53
D. 51.3
44. The average of 6 numbers is 18. If two numbers are added, the average becomes 20. If added numbers are equal, find their value.
A. 38
B. 26
C. 44
D. 42
45. The arithmetic mean of numbers 3, 7, 11, …, up to n terms equals 52. If the sequence is AP with first term 3 and common difference 4, how many terms?
A. 26
B. 25
C. 24.5
D. 27
46. A library has 5 shelves. Averages of books per shelf are 48, 52, 46, 50 and x. If the overall average per shelf is 50, find x.
A. 50
B. 54
C. 48
D. 56
47. A company’s monthly salaries for 10 employees average to ₹45,000. Two senior employees earn ₹80,000 and ₹90,000; if they are excluded average becomes ₹40,000. What was the total salary of the 2 seniors?
A. ₹130,000
B. ₹170,000
C. ₹160,000
D. ₹180,000
48. The average of five numbers is 20. The first is twice the second; the third is the second plus 3; the fourth equals the third and the fifth is 2. Which is the second number?
A. 6
B. 18.4
C. 5
D. 7
49. Average of 200 numbers is 250. If one more number increases the average to 251, the added number is:
A. 450
B. 650
C. 451
D. 251
50. The average of seven consecutive even integers is 48. The middle number is:
A. 48
B. 48
C. 50
D. 46
51. Average of prices of 12 items is ₹240. After a 10% price increase on each item, new average is:
A. ₹266.4
B. ₹264
C. ₹260
D. ₹270
52. A team’s average score across 5 matches is 36. If in the 6th match they score 64, new average becomes:
A. 38.63
B. 40.67
C. 39.58
D. 37.96
53. The average of the digits of a 3-digit number ABC (digits A, B, C) is 6 and A = B + 2, C = B – 1. Find B.
A. 5.6
B. 4.6
C. 6.9
D. 3.5
54. The average of n values is 100. Adding k numbers each equal to 80 decreases the average to 95. If k = 5, find n.
A. 20
B. 15
C. 10
D. 25
55. The average of 4 consecutive multiples of 3 is 21. The smallest multiple is:
A. 15
B. 16.5
C. 18.6
D. 12
56. A set of 14 numbers has average 30. The average of first 7 numbers is 26. What is the average of the remaining 7 numbers?
A. 44
B. 34
C. 33
D. 32
57. The mean of x, x+4, 2x-2 is 30. Solve for x.
A. 22
B. 20
C. 18
D. 16
58. The average of two numbers is 84 and their difference is 12. The numbers are:
A. 90 and 88
B. 90 and 78
C. 86 and 74
D. 88 and 76
59. The harmonic mean of 2 numbers is 9 and their arithmetic mean is 13. The numbers are? (Pick the consistent pair)
A. 10 and 16
B. 12 and 14
C. 9 and 17
D. 20.21 and 5.78
60. Average of 20 items is 48. If 5 items each of value 60 are replaced by five items each of value 36, new average becomes:
A. 46.5
B. 46
C. 45.5
D. 42
61. A team’s batting average over 9 innings is 24. If in the 10th inning they score 78 the average becomes 29. What did they score in the 10th inning? (Check consistency)
A. 78
B. 74
C. 78
D. 72
62. Average of five numbers is 82. If four of them are 76, 84, 90 and 70 what is the fifth?
A. 90
B. 78
C. 74
D. 76
63. Averages of monthly sales for Jan–Mar are 1200, 1500, 1800. If combined average for the quarter is 1500, what are month sizes if Jan had 4 branches, Feb 6 branches and Mar 10 branches? (Find weighted average)
A. 1560
B. 1560
C. 1590
D. 1520
64. The average of 6 numbers is 15. If two numbers 12 and 18 are removed and replaced by 22 and x and average remains unchanged, find x.
A. 12
B. 20
C. 16
D. 8
65. An exam average for 300 students is 72. If 30 absentees (who averaged 0) are included, new average becomes:
A. 64.2
B. 65.2
C. 65.45
D. 65.0
66. A set contains integers 10 to 30 inclusive. What is its average?
A. 20
B. 20
C. 21
D. 19.5
67. If average of numbers a, b, c is 84 and a = b + 10, c = b – 4, find b.
A. 60
B. 58
C. 59
D. 82
68. The average of 8 numbers is 75. Removing the highest and lowest (which differ by 30) makes the average 78. Sum of highest and lowest is:
A. 96
B. 126
C. 90
D. 132
69. Two classes have averages 68 (20 students) and 75 (15 students). A new student transfers from first class to second and the average of new combined class becomes 72. The transferred student’s score is:
A. 72
B. 82
C. 70
D. 74
70. The average of a, b, c, d is 95. If a = 70 and b = 110 and c = d, find c.
A. 90
B. 100
C. 95
D. 92
71. A sequence of 7 consecutive multiples of 5 has average 45. The middle multiple equals:
A. 55
B. 45
C. 50
D. 40
72. If nine numbers have average 50 and three numbers 40, 60, 80 are added, the new average is:
A. 54
B. 52.5
C. 53
D. 55
73. The mean of 12 numbers is 48. If two numbers are decreased by 6 and increased by 10 respectively, the new mean is:
A. 49
B. 48.33
C. 48.67
D. 47.67
74. A group of 6 friends has an average age of 28. If one friend aged 30 leaves, what should be the age of a new friend joining so that average becomes 29?
A. 34
B. 36
C. 32
D. 38
75. The average of 21 numbers is 84. If one number is replaced by 77, the average drops by 1. Find the removed number.
A. 106
B. 98
C. 92
D. 100
76. In a set of 5 numbers, average is 200. If the largest number is twice the smallest and the middle three are all equal to 190, find smallest number.
A. 120
B. 86
C. 100
D. 130
77. Average of numbers 1 to 101 (inclusive) is:
A. 51
B. 51
C. 50.5
D. 52
78. The average of four numbers is 63. If three of them are 61, 67 and 59, the fourth is:
A. 68
B. 65
C. 69
D. 70
79. Averages of two sets are 34 (size 10) and 46 (size m). If combined average equals 40 and m < 20, find m.
A. 8
B. 10
C. 12
D. 9
80. A manager’s monthly average sales over 4 months is 120. In next month sales are 200 increasing the overall average to 130. What was the total of first 4 months?
A. 480
B. 540
C. 500
D. 520
81. The average temperature for 7 days is 22°C. If on one day temperature is 30°C and is removed, the average becomes 20°C. What is the sum of the remaining 6 days?
A. 20.66
B. 120
C. 126
D. 116
82. The mean of first 10 prime numbers is approximately:
A. 12.1
B. 11.9
C. 11.9
D. 12.9
83. The average of five numbers is 64. If one number is doubled, the new average increases by 8. Find the number doubled.
A. 40
B. 56
C. 52
D. 60
84. The average of 3 consecutive odd numbers is 49. The numbers are:
A. 47, 49, 51
B. 47, 49, 51
C. 45, 49, 53
D. 49, 51, 53
85. A set of 24 values has mean 36. If 4 values each equal to 30 are replaced by 4 values each equal to 54, new mean becomes:
A. 40
B. 39
C. 39
D. 37
86. Average of three numbers is 94. If first decreases by 6, second increases by 12 and third remains unchanged, new average becomes 96. Find the first number.
A. 84
B. 90
C. 88
D. Insufficient Data
87. Ten numbers have average 60. If each number is increased by 10% the new average becomes:
A. 766
B. 66
C. 70
D. 63
88. The average of three ages is 30. If each age is doubled, average becomes:
A. 160
B. 60
C. 58
D. 62
89. The mean of two classes is 41. If one class average is 38 (size 20) and the combined size is 50, what is the other class average?
A. 42.5
B. 43
C. 44.5
D. 45.0
90. Average of six numbers is 24. If two numbers are 18 and 30, and three others are equal, find the common value.
A. 24
B. 26
C. 22
D. 28
91. The average of 16 numbers is 47. If each number is reduced by 7, the new average is:
A. 40
B. 40.5
C. 41
D. 39
92. Average of 7 numbers is 51. If two numbers are 65 and 35, find average of the remaining 5 numbers.
A. 49.6
B. 48.8
C. 51.4
D. 47.2
93. The mean of five numbers is 203. If four numbers are 200, 210, 205 and 198, find the fifth.
A. 202
B. 205
C. 205
D. 203
94. Average score of 4 players is 36. If three players scored 24, 28, 46, find the fourth.
A. 46
B. 54
C. 52
D. 50
95. A dataset has even numbers from 2 to 40 inclusive. The mean is:
A. 21
B. 23
C. 20
D. 22
96. The average of three numbers is 34. If two of them are 28 and 40, the third is:
A. 38
B. 34
C. 36
D. 32
97. Average of ages of a father and his son is 34. If father is 38 years older than son, find son’s age.
A. 15
B. 8
C. 16
D. 12
98. In a set of 10 values, average is 100. If one value is replaced by 190, the average increases by 9. The replaced value was:
A. 100
B. 20
C. 10
D. 15
99. The average of five numbers is 15. If each number is increased by its position in the sequence (1 to 5), new average is:
A. 18
B. 28
C. 17
D. 19
100. A dataset contains 11 numbers with mean 64. One number is incorrectly copied as 46 instead of 64. What is the correct mean after correction?
A. 65.636… (≈65.64)
B. 65.00
C. 66.00
D. 65.27