SSC CHSL 6 Dec 2015 Shift 1 Paper

Let Jais's present age = x years
Jais's father's present age = ( x +35) years
Sum of their ages after 5 years = $\left(\mathit{x}+5\right)+\left(\mathit{x}+35+5\right)=125$
⇒ $2\mathit{x}+45=125$
⇒ $2\mathit{x}=125-45=80$
⇒ $\mathit{x}=\frac{80}{2}=40$
∴ Age of jais and his father after 12 years from now = $\left(\mathit{x}+12\right)$ and $\left(\mathit{x}+35+12\right)$
= 52 and 87 years