SSC CHSL 20 Dec 2015 Shift 1 Paper

Let the angle be A
Complement of an angle with A is given by $\left(90°-\mathit{A}\right)$
Supplement of an angle with A is given by $\left(180°-\mathit{A}\right)$
Now equation can be written as,
$90°-\mathit{A}=\frac{1}{4}\left(180°-\mathit{A}\right)$
$90°-\mathit{A}=\left(45°-\frac{\mathit{A}}{4}\right)$
$\mathit{A}\left(1-\frac{1}{4}\right)=45°$
A = 60°
Hence, option B is the correct answer.