Question

5 years ago, father’s age was 7 times the age of his son. 5 years later, the father’s age
will be 3 times the age of his son. Find their present ages.

Answer 1

Answer:

Let x be the present age of the father and y be the present age of the son.

After five years, the father’s age will be (x+5) and the age of son will be (y+5), then,

x+5=3(y+5)

x−3y−10=0 .... (1)

Five years ago, the age of the father was (x−5) and son’s age was (y−5), so,

(x−5)=7(y−5)

x−7y+30=0 .... (2)

From subtracting equation (1) from (2),

−3y+7y−10−30=0⇒y=10

Putting y=10 in (1),

x−3(10)−10=0⇒x=40

Therefore, the present age of father is 40 years and that of son is 10 years.

Answer 2

Answer:

Five years hence, a man's age will be three times the age of his son. Five years ago, the man was seven times as old as his son. And His son's be y years. Hence, man's present age = 40 years and son's present age = 10 years.