This set of Aptitude Questions and Answers (MCQs) focuses on “Average”. These questions are beneficial for various competitive exams, placement interviews, and entrance tests.
1. The average age of 5 men is 40. The average age of 5 women is 39. The average age of their 4 children is 15. What is the average age of a family?
a) 45
b) 30.33
c) 90.5
d) 91
View Answer
Explanation: Average age of the families = (total age of men + total age of women + total age of children) / number of families {Here, the average age of the entire family is asked}
(5 * 40 + 5 * 39 + 4 * 15) / 5
200 + 195 + 60) / 5
455 / 5 = 91
2. The average age of 20 men is 50. The average age of their wives is 44. 3 couples among them have two children rest have one child. The average age of each child is 19 years. Find the average age of a family.
a) 11.575
b) 115.85
c) 115.75
d) 11.585
View Answer
Explanation: Total age of men = 20 * 50 = 1000
Total age of women = 20 * 44 = 880
Total number of children = 2 * 3 + (20 – 3) = 23 (as three couples have two children rest have one child)
Total age of children = 23 * 19 = 437
Average age of the family = (1000 + 880 + 437) / 20 = 115.85.
3. The total age of 5 men is 440. The total age of their wives is 385. The average age of their children is 22. What is the average age of each member of the family? (each couple have 3 children)
a) 44.5
b) 56.2
c) 46.2
d) 50.2
View Answer
Explanation: Total number of children 5 * 3 = 15
Average age of each child is 22.
Total age of the children is 22 * 15 = 330.
Total age of all the people = 330 + 440 + 385 = 1155.
Average age of each member = 1155 / (5 + 5 + 15) = 1155 / 25 = 46.2 (Here, in the question it was asked the average age of each member of the family and not the entire family).
4. The age of 5 people are in proportion 2:3:4:10:11. If their average age is 18, find the average age of the eldest of them.
a) 11
b) 22
c) 33
d) 44
View Answer
Explanation: The eldest person has a share of 11 from the proportion, so, let the age of the eldest from them be 11x.
The total of the proportion = (2 + 3 + 4 + 10 + 11) x = 30x
The average of the proportion = 30x / 5 = 6x
Average age as per proportion = 6x
Average age given = 18
On putting values, 6x = 18, x = 3
The age of the eldest person = 11x = 11 * 3 = 33.
5. The ages of 5 people are in a ratio 1:3:5:7:11. If the difference between the total of their age and the average of their ages is 108, find the age of the Youngest of them.
a) 5
b) 10
c) 15
d) 12
View Answer
Explanation: Let each share be in terms of x.
The total share = x + 3x + 5x + 7x + 11x = 27x
The average share = 27x / 5 = 5.4x
The difference between total share and average share is 108 (given in the question).
27x – 5.4x = 21.6x = 108
X = 108 / 21.6 = 5
6. The average age of 9 members of a family is 68. If a couple with average age 45 left the house and another couple is blessed with twins, what will be the average age of the family 5 years later?
a) 53
b) 57
c) 60
d) 63
View Answer
Explanation: The total age of the family now = 9 * 68 = 612
The age of the couple left = 45 * 2 = 90
The total age now = 612 – 90 = 522
The total age 5 years hence = 522 + (9 * 5) = 522 + 45 = 567 (the number of people in the family remains constant as two people left, and a pair of twins was born the same year).
The average age of the family = 567 / 9 = 63.
7. The average runs scored by Rohan in first 11 matches is 97. If he scored x runs in his 12th match the average decreased by 3. Find the value of x.
a) 57
b) 59
c) 61
d) 63
View Answer
Explanation: Total runs scored by Rohan in first 11 matches = 11 * 97 = 1067
His average after 12 matches = 97 – 3 = 94
His total score after 12 matches = 94 * 12 = 1128
His score in 12th match = total runs in 12 matches – total runs in 11 matches = 1128 – 1067
= 61
8. Ravi travelled 290 km in three parts 100 km at a speed of 20 kmph, 120 km at a speed of 80 kmph and remaining at a speed of 140 kmph. Find his average speed during the journey.
a) 40.42
b) 41.42
c) 40.47
d) 41.47
View Answer
Explanation: Total distance covered = 290 km
Total time taken:
100 km at 20 kmph will take 100 / 20 = 5 hours
1280 km at 90 kmph will take 120 / 80 = 1.5 hours
Remaining = 290 – 100 – 120 = 70
70 km at 140 kmph will take 70 / 140 = 0.5 hours
Total time taken = 5 + 1.5 + 0.5 = 7 hours
Average speed = total distance covered / total time taken
= 290 / 7 = 41.42
9. Raj have 5 members in his team excluding him. When arranged in ascending order the difference between every second person was equal to 3. If the average of their ages is 45, find the age of Raj if he is 4th eldest amongst the team.
a) 33
b) 36
c) 39
d) 42
View Answer
Explanation: Let the difference be x. And the members be o, p, q, r, s.
Given that the difference between everyone is equal that is 3.
So, the sum of their ages be 5(o) + 3 + 6 + 9 + 12 + 15 = 5(o) + 45
Total age = 45 * 5 = 225 = 5(o) + 45
5(o) = 225 – 45 = 180
o = 180 / 5 = 36
Raj is 4th eldest that is the 2nd youngest.
Raj’s age = o + common difference = 36 + 3 = 39.
10. Find the average of the prime numbers between 100 and 200.
a) 140.33
b) 141.33
c) 142.33
d) 143.33
View Answer
Explanation: List of prime numbers between 100 and 200:
101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197 and 199.
Total sum = 2968
Total count = 21
Average = 2968 / 21 = 141.33
More Aptitude Questions and Answers on Average:
- Average Questions (Set 2)
- Average Questions (Set 3)
- Average Questions (Set 4)
- Average Questions (Set 5)
To practice all aptitude questions, please visit “1000+ Quantitative Aptitude Questions”, “1000+ Logical Reasoning Questions”, and “Data Interpretation Questions”.
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