Sainik School Entrance Exam 2020 Solved Paper

(a) Suppose that two years ago, age of his son$=\mathit{a}\mathrm{years}$
Then, Dilip's age $=3\mathit{a}\mathrm{years}$
∴ Present age of his son $=\mathit{a}+2$,
and Dilip's age $=3\mathit{a}+2$
Two years hence,
$2\left(3\mathit{a}+4\right)=5\left(\mathit{a}+4\right)$
$\Rightarrow 6\mathit{a}+8=5\mathit{a}+20$
$\Rightarrow 6\mathit{a}-5\mathit{a}=20-8$
$\Rightarrow \mathit{a}=12\mathrm{years}$
∴ The present age of son
$=\mathit{a}+2=12+2=14\mathrm{years}$
and present age of Dilip
$=3\mathit{a}+2=3\times 12+2$
$=38\mathrm{years}$ .