Question

Four years ago, the sum of ages of father and his son was 27 years. After five years, the ratio of the ages of the son and father will be 2: 7. Find the present ages of father and his son. Ans: 30 yrs, 5 yrs​

Answer 1

Explanation:

x current age of the father

y current age of the son

first equation (x-4)+(y-4)=27 so x=27+4+4-y=35-y

second equation (y+5) : (x+5)= 2:7

so (y+5)*7=(x+5)*2

let's replace x we found at the first equation with the one at second equation

(y+5)*7=(35-y+5)*2

7y+35=(40-y)*2

7y+35=80-2y

7y+2y=80-35

9y=45

y=5

x=35-y=35-5=30