Liquid Solution

A solution of non volatile solute is obtained by dissolving 2 g in 50 g benzene. Calculate the vapour pressure of solution if vapour pressure of pure benzene is 640 mmHg at $25^{\circ} \mathrm{C}$.
[mol. mass of benzene $=78 \mathrm{~g} \mathrm{~mol}^{-1}$, mol. mass of solute $\left.=64 \mathrm{~g} \mathrm{~mol}^{-1}\right]$