Question

A father's age is thrice the sum of ages of his two children. After 5 years his age will be twice the sum of the ages of his two children. Find the present age of the father.

Answer 1

Let father's age be x & sum of children's age $=y$

$x=3y$

$(x+5)=2(y+5)$

$\Rightarrow 3y+5=2y+10$

$\Rightarrow y=5$

So $x=3y$

$x=15$.