Question

The ratio between the ages of a father and a son at present is 5 : 2 respectively. Four year hence the ratio between the ages of the son and his mother will be 1 : 2 respectively. What is the ratio between the present ages of the father and the mother respectively ?

Answer 1

Let the present age of son be 2x then father's age is 5x.four years later the age of son is 2x+4.As then the ratio of ages of son and the mother is 1:2=> the age of mother will then be 2(2x+4)=4x+8.So the present age of mother=4x+8–4=4(x+1).As present age of father is 5x.Hence the ratio of father to son=5x:4(x+1),where x is the age of son.