Liquid 'M' and liquid 'N' form an ideal solution.

Liquid 'M' and liquid 'N' form an ideal solution. The vapour pressures of pure liquids 'M' and ' $\mathrm{N}$ ' are 450 and $700 \mathrm{mmHg}$, respectively, at the same temperature. Then correct statement is:

$\left(x_{\mathrm{M}}=\right.$ Mole fraction of 'M' in solution ;

$x_{\mathrm{N}}=$ Mole fraction of 'N' in solution ;

$y_{\mathrm{M}}=$ Mole fraction of 'M' in vapour phase ;

$y_{\mathrm{N}}=$ Mole fraction of ' $\mathrm{N}$ ' in vapour phase)