Question

The sum of the age of a father and
his son is 100 years now. 5 years ago
their age were in the ratio of 2:1. The
ratio of the age of father and son
after 10 years will be
​

Answer 1

Answer :

25 : 9

Solution :

Let,

Age of father be 'x'.

Age of son be 'y'.

Given,

Sum of age of father and son = 100

x + y = 100

x = 100 - y

Five years ago,

Ratio of their ages = 2 : 1

(x-5) : (y-5) = 2 : 1

(x-5)/(y-5) = 2/1

Substitute x = 100 - y

(100 - y)-5/y - 5 = 2

100 - y = 2y - 10 + 5

100 + 5 = 3y

y = 35

x = 100 - y

x = 100 - 35

x = 65

Ratio of their ages after 10 yrs

= (65 + 10) : (35 + 10)

= 75 : 45

= 25 : 9