Question

The average age of a man and his son is 38 years.10years ago, the ratio of their ages was 5:2.What is the age of the son?

Answer 1

Hi!
Here is the Solution:


Since there are only two persons , so, the sum of ages is 38x2 = 76
Now we proceed to find out the ages of the father and the son.

Let the father's age be X
And Son's age will be (76-X)

10 years ago
Father's age was (X-10)
Son's age was (76-x -10) = (66-X)

ACQ
(X -10)/(66-X) = 5/2

2X -20 = 330 -5X
2X +5X = 330 +20
7X = 350
X= 350/7
X= 50

So, The father's age is 50 years
And Son's age is (76 -X) = 26 years

________________________________
Any problem in understanding the solution, feel free to ask in the comment box.

Answer 2

average = sum / number of person
38 = (man + son) / 2
age of man + son = 38×2 = 76
10 years ago, both persons age was (10+10) = 20 year less than the present age. so 10 year ago, age was 76-20 = 56
and ratio of man and son was 5:2
so divide the 56 year in ratio 5:2
man age = (5/7)×56 = 40-------- 10 year ago
son age = (2/7)×56=16------------10 year ago
present age of son = 16+10 = 26 year