Aptitude Average Medium Set 1
Practice free Average aptitude MCQ questions with answers — medium level, covering weighted averages, average speed, run rate calculations, income and salary problems, misread corrections, and algebraic mean concepts. This 30-question aptitude test is designed to sharpen your problem-solving speed and accuracy for the quantitative sections of competitive exams. Attempt all questions and check your answers instantly with clear explanations.
Q1.After replacing an old member by a new member, it was found that the average age of six members of a club is the same as it was 2 years ago. What is the difference between the ages of the replaced and the new member?
View Solution & Explanation
If the same 6 members had remained in the club, then in 2 years total age would increase by 6*2 = 12 years.
But the average is the same as it was 2 years ago.
So, this increase of 12 years must be cancelled by replacing an older member with a younger member.
Difference between replaced member and new member = 12 years
Q2.The average income of P, Q and R is Rs. 21,000 per month and average income of Q, R and S is Rs. 27,000 per month. If the average salary of S is twice that of P, then the average salary of Q and R is in Rs. :
View Solution & Explanation
P + Q + R = 21,0003 = 63,000
Q + R + S = 27,0003 = 81,000
So, S - P = 81,000 - 63,000 = 18,000
Given S = 2P
So, 2P - P = 18,000
P = 18,000
Then Q + R = 63,000 - 18,000 = 45,000
Average of Q and R = 45,000/2 = 22,500
Q3.There are two sections A and B of a class, consisting of 25 and 15 students respectively. If the average weight of section A is 52 kg and that of section B is 40 kg, find the average weight of the whole class.
View Solution & Explanation
Total weight of section A = 25*52 = 1300 kg
Total weight of section B = 15*40 = 600 kg
Total weight = 1300 + 600 = 1900 kg
Total students = 25 + 15 = 40
Average weight = 1900/40 = 47.5 kg
Q4.Six numbers are arranged in decreasing order. The average of the first five numbers is 42 and the average of the last five numbers is 35. The difference of the first and the last numbers is
View Solution & Explanation
Sum of first five numbers = 42*5 = 210
Sum of last five numbers = 35*5 = 175
Difference = 210 - 175 = 35
So, difference of first and last numbers = 35
Q5.The average of runs of a cricket player of 10 innings was 28. How many runs must he make in his next innings so as to increase his average of runs by 4?
View Solution & Explanation
Total runs in 10 innings = 10*28 = 280
New average = 28 + 4 = 32
Total runs needed in 11 innings = 11*32 = 352
Runs needed in next innings = 352 - 280 = 72
Q6.The average age of seven boys sitting in a row facing North is 24 years. If the average age of the first three boys is 20 years and the average age of the last three boys is 27 years, what is the age of the boy who is sitting in the middle of the row?
View Solution & Explanation
Total age of 7 boys = 7*24 = 168
Total age of first 3 boys = 3*20 = 60
Total age of last 3 boys = 3*27 = 81
Age of middle boy = 168 - 60 - 81 = 27 years
Q7.The average marks obtained by 26 candidates in an examination are 48. The average marks of the first twelve are 52 and that of the last thirteen are 44. The number of marks obtained by the 13th candidate is-
View Solution & Explanation
Total marks of 26 candidates = 26*48 = 1248
Total marks of first 12 candidates = 12*52 = 624
Total marks of last 13 candidates = 13*44 = 572
Marks of 13th candidate = 1248 - 624 - 572 = 52
Q8.The mean monthly salary paid to 80 workers in a factory is Rs. 6200. The mean salary of 30 of them is Rs. 6000 and that of 25 others is Rs. 6400. The mean salary of the remaining workers is-
View Solution & Explanation
Total salary of 80 workers = 80*6200 = 496000
Salary of 30 workers = 30*6000 = 180000
Salary of 25 workers = 25*6400 = 160000
Salary of remaining workers = 496000 - 180000 - 160000 = 156000
Number of remaining workers = 80 - 30 - 25 = 25
Mean salary of remaining workers = 156000/25 = 6240
Q9.Average score of a class of 50 students, in an exam, was 44. Average score of the students who had passed is 50 and the average score of students who had failed is 20. How many failed the exam?
View Solution & Explanation
Total score of class = 50*44 = 2200
Let failed students = x
Passed students = 50 - x
Total score = 50*(50 - x) + 20*x
2200 = 2500 - 50*x + 20*x
2200 = 2500 - 30*x
30*x = 300
x = 10
Q10.The mean high temperature of the first four days of a week is 24°C whereas the mean of the last four days is 25°C. If the mean of the whole week is 24.4°C, then the temperature of the 4th day is-
View Solution & Explanation
Sum of first 4 days = 4*24 = 96
Sum of last 4 days = 4*25 = 100
So, total = 96 + 100 = 196
Here, 4th day is counted twice.
Sum of whole week = 7*24.4 = 170.8
Temperature of 4th day = 196 - 170.8 = 25.2°C
Q11.Students of three different classes appeared in a common examination. Pass average of 8 students of first class was 75%, pass average of 12 students of second class was 65% and pass average of 20 students of third class was 85%. What will be the pass average of all students of the three classes?
View Solution & Explanation
Total marks percentage of first class = 875 = 600
Total marks percentage of second class = 1265 = 780
Total marks percentage of third class = 20*85 = 1700
Total = 600 + 780 + 1700 = 3080
Total students = 8 + 12 + 20 = 40
Overall average = 3080/40 = 77%
Q12.There are two sections A and B of a class, consisting of 18 and 22 students respectively. If the average weight of section A is 45 kg and that of section B is 35 kg, find the average weight of the whole class.
View Solution & Explanation
Total weight of section A = 18*45 = 810 kg
Total weight of section B = 22*35 = 770 kg
Total weight = 810 + 770 = 1580 kg
Total students = 18 + 22 = 40
Average weight = 1580/40 = 39.5 kg
Q13.The marks of six boys in a group are 52, 61, 74, 45, 68 and 60. What are the average marks of all six boys?
View Solution & Explanation
Total marks = 52 + 61 + 74 + 45 + 68 + 60 = 360
Average = 360/6 = 60
Q14.The average of two numbers is PQ. If one number is P, the other is-
View Solution & Explanation
Average = PQ
So, sum of two numbers = 2*P*Q
One number = P
Other number = 2*P*Q - P
Other number = P*(2Q - 1)
Q15.A man started his journey from Jaipur to Delhi, which is 120 km, at the speed of 60 kmph. Then he went to Agra which is 180 km, at the speed of 45 kmph. Further he went to Bhopal which is 300 km, at the speed of 30 kmph. The average speed of the man is :
View Solution & Explanation
Time from Jaipur to Delhi = 120/60 = 2 hours
Time from Delhi to Agra = 180/45 = 4 hours
Time from Agra to Bhopal = 300/30 = 10 hours
Total distance = 120 + 180 + 300 = 600 km
Total time = 2 + 4 + 10 = 16 hours
Average speed = 600/16 = 37.5 kmph
Q16.In the first 10 overs of a cricket game, the run rate was only 4.6. What should be the run rate in the remaining 40 overs to reach the target of 290 runs?
View Solution & Explanation
Runs scored in first 10 overs = 10*4.6 = 46
Runs needed to reach target = 290 - 46 = 244
Required run rate in remaining 40 overs = 244/40 = 6.1
Q17.The average marks in Science subject of a class of 30 students is 74. If the marks of two students were misread as 56 and 63 instead of the actual marks 81 and 68 respectively, what would be the correct average?
View Solution & Explanation
Wrong total marks = 30*74 = 2220
Actual increase = 81 + 68 - 56 - 63
Actual increase = 149 - 119 = 30
Correct total marks = 2220 + 30 = 2250
Correct average = 2250/30 = 75
Q18.A grocer has a sale of Rs. 5200, Rs. 6100, Rs. 5800, Rs. 6400 and Rs. 5500 for 5 consecutive months. How much sale must he have in the sixth month so that he gets an average sale of Rs. 6000?
View Solution & Explanation
Total sale needed for 6 months = 6*6000 = 36000
Sale of first 5 months = 5200 + 6100 + 5800 + 6400 + 5500
Sale of first 5 months = 29000
Sale needed in sixth month = 36000 - 29000 = 7000
Q19.The arithmetic mean of first 21 natural numbers is
View Solution & Explanation
First 21 natural numbers are from 1 to 21
Arithmetic mean = (1 + 21)/2 = 22/2 = 11
Q20.In Rohan’s opinion, his weight is greater than 58 kg but less than 66 kg. His sister does not agree with Rohan and she thinks that Rohan’s weight is greater than 60 kg but less than 70 kg. His father’s view is that his weight cannot be greater than 64 kg. If all of them are correct in their estimation, what is the average of different probable weights of Rohan?
View Solution & Explanation
From first opinion, weight can be 59, 60, 61, 62, 63, 64, 65
From second opinion, weight can be 61, 62, 63, 64, 65, 66, 67, 68, 69
From third opinion, weight cannot be more than 64
Common probable weights = 61, 62, 63, 64
Average = (61 + 62 + 63 + 64)/4
Average = 250/4 = 62.5 kg
Q21.If the mean of x, y, z is N and xy + yz + zx = 0, then the mean of x<sup>2</sup>, y<sup>2</sup>, z<sup>2</sup> is -
View Solution & Explanation
Mean of x, y, z = N
So, x + y + z = 3*N
Now,
(x + y + z)*(x + y + z) = x*x + y*y + z*z + 2*(xy + yz + zx)
Given xy + yz + zx = 0
So, x*x + y*y + z*z = (3*N)*(3*N) = 9*N*N
Mean of x2, y2, z2 = 9*N*N/3 = 3*N*N
Q22.The average of 4, 9, 7 and p is 8 and the average of 20, 3, 7, p and q is 11. What is the value of q?
View Solution & Explanation
Average of 4, 9, 7 and p is 8
So, total = 8*4 = 32
Thus, p = 32 - 4 - 9 - 7 = 12
Now, average of 20, 3, 7, p and q is 11
So, total = 11*5 = 55
q = 55 - 20 - 3 - 7 - 12
q = 13
Q23.The mean of 14, 24, 34, 44, 54, 64, 74 is -
View Solution & Explanation
These numbers are in arithmetic sequence.
Mean = first number + last number / 2
Mean = (14 + 74)/2 = 88/2 = 44
Q24.The average of a non-zero number and its square is 4 times the number. The number is-
View Solution & Explanation
Let the number be n
Average of n and n*n = 4*n
So, (n + n*n)/2 = 4*n
n + n*n = 8*n
n*n - 7*n = 0
n*(n - 7) = 0
Given number is non-zero
So, n = 7
Q25.If the average weight of 6 students is 48 kg. If two students of average weight of 52 kg are added and two other students of average weight of 56 kg are also added then the average weight of all the students is :
View Solution & Explanation
Total weight of first 6 students = 6*48 = 288 kg
Total weight of next 2 students = 2*52 = 104 kg
Total weight of other 2 students = 2*56 = 112 kg
Total weight = 288 + 104 + 112 = 504 kg
Total students = 6 + 2 + 2 = 10
Average weight = 504/10 = 50.4 kg
Q26.A fruit seller sold big, medium and small sizes mangoes of Rs. 25, Rs. 15 and Rs. 5, respectively. The total number of mangoes sold were in the ratio 4 : 3 : 3. Find the average cost of a mango.
View Solution & Explanation
Take numbers sold as 4, 3 and 3
Total cost = 4*25 + 3*15 + 3*5
Total cost = 100 + 45 + 15 = 160
Total mangoes = 4 + 3 + 3 = 10
Average cost = 160/10 = 16
Q27.In a pre school, the average weight of 24 girls in a class among 40 students is 18 kg and that of the remaining students is 17 kg. What is the average weight of all the students in the class?
View Solution & Explanation
Total weight of 24 girls = 24*18 = 432 kg
Remaining students = 40 - 24 = 16
Total weight of remaining students = 16*17 = 272 kg
Total weight = 432 + 272 = 704 kg
Average weight = 704/40 = 17.6 kg
Q28.A man purchased 6 bags of rice at the rate of Rs. 900 each, 9 bags of rice at Rs. 1100 each and 5 bags of rice at the rate of Rs. 1300 each. What is the average cost of one bag of rice?
View Solution & Explanation
Total cost = 6*900 + 9*1100 + 5*1300
Total cost = 5400 + 9900 + 6500 = 21800
Total bags = 6 + 9 + 5 = 20
Average cost per bag = 21800/20 = 1090
Q29.The average marks obtained by 24 candidates in an examination are 50. The average marks of the first 9 candidates is 54 and those of the last 14 candidates is 48. The number of marks obtained by the tenth candidate is ?
View Solution & Explanation
Total marks of 24 candidates = 24*50 = 1200
Marks of first 9 candidates = 9*54 = 486
Marks of last 14 candidates = 14*48 = 672
Marks of tenth candidate = 1200 - 486 - 672 = 42
Q30.The average of a collection of 20 measurements was calculated to be 60 cm. But later it was found that a mistake had occurred in one of the measurements which was recorded as 66 cm, but should have been 62 cm. The correct average must be -
View Solution & Explanation
Wrong total = 20*60 = 1200 cm
Recorded value was 66 cm, but correct value is 62 cm
So, total must be reduced by 66 - 62 = 4 cm
Correct total = 1200 - 4 = 1196 cm
Correct average = 1196/20 = 59.8 cm
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