$A$ mixture of benzene and toluene forms

Liquid $M$ and liquid $N$ form an ideal solution. The vapour pressures of pure liquids $M$ and $N$ are $450 \ mmHg$ and $700 \ mmHg,$ respectively at the same temperature. Then the correct statement is: ( $x_M =$ mole fraction of $M$ in solution; $x_N =$ mole fraction of $N$ in solution; $y_M =$ mole fraction of $M$ in vapour phase; $y_N =$ mole fraction of $N$ in vapour phase)

What is vapour pressure? And what is an ideal solution?

$A$ solution of acetone in ethanol:

If liquids $A$ and $B$ form an ideal solution,which of the following statements is true?

Which of the following does not show positive deviation from Raoult's law?