NIFT UG 2015 Question Paper with solutions

Let, present age of Mukesh and Sailee are x and y years respectively.
Five years earlier,
$\mathit{x}\mathit{–}5=7\left(\mathit{y}\mathit{–}5\right)$
$\Rightarrow \mathit{x}\mathit{–}7\mathit{y}=\mathit{–}30$....(i)
After 15 years,
$\mathit{x}+15=3\left(\mathit{y}+15\right)$
$\Rightarrow \mathit{x}\mathit{–}3\mathit{y}=30$...(ii)
From (i) and (ii), we have,
$\mathit{x}=5\mathit{y}$
∴ x = 75, y = 15
Then $\mathit{x}+\mathit{y}=75+15=90$ years