You are asked to design a shaving mirror assuming that a person keeps it $10\; cm$ from his face and views the magnified image of the face at the closest comfortable distance of $25\; cm$. The radius of curvature of the mirror would then be :

Question

$\begin{array}{1 1} 30\;cm \\ 24\;cm \\ 60\;cm \\ -24\;cm \end{array} $