Assuming ideal behaviour,the enthalpy and volume of mixing of two liquids respectively,are

Which of the following is true when components forming an ideal solution are mixed?

An ideal solution was obtained by mixing methanol and ethanol. If the partial vapour pressure of methanol and ethanol are $2.619 \, kPa$ and $4.556 \, kPa$ respectively,the composition of the vapour (in terms of mole fraction) will be

At $300 \ K$,the vapour pressure of a pure liquid $A$ is $70 \ mm \ Hg$. It forms an ideal solution with another liquid $B$. The mole fraction of $B$ in the solution is $0.2$ and the total vapour pressure of the solution is $84 \ mm \ Hg$ at the same temperature. What is the vapour pressure (in $mm \ Hg$) of pure liquid $B$ at $300 \ K$?

$A$ liquid mixture is an ideal solution, if
$(I)$ It obeys ideal gas equation
$(II)$ It obeys Raoult's law at all concentrations
$(III)$ Solute - solute, solute - solvent and solvent - solvent interactions are similar

Which of the following is not an ideal solution?