Which from the following liquid mixtures behaves nearly as an ideal solution?

At a particular temperature,the vapour pressures of two liquids $A$ and $B$ are respectively $120 \, mm$ and $180 \, mm$ of mercury. If $2 \, moles$ of $A$ and $3 \, moles$ of $B$ are mixed to form an ideal solution,the vapour pressure of the solution at the same temperature will be (in $mm$ of mercury):

At $300 \ K$,the vapour pressures of $A$ and $B$ liquids are $500 \ mm \ Hg$ and $400 \ mm \ Hg$ respectively. Equal moles of $A$ and $B$ are mixed to form an ideal solution. The mole fraction of $A$ and $B$ in the vapor state is respectively:

Liquids $A$ and $B$ form an ideal solution for all compositions of $A$ and $B$ at $25^{\circ} C$. Two such solutions with $0.25$ and $0.50$ mole fractions of $A$ have total vapor pressures of $0.3 \ bar$ and $0.4 \ bar$,respectively. What is the vapor pressure of pure liquid $B$ in $bar$?

Total vapour pressure of a mixture of $1 \, mol \, X$ $(P_x^o = 150 \, torr)$ and $2 \, mol \, Y$ $(P_y^o = 300 \, torr)$ is $240 \, torr$. In this case:

Liquids $A$ and $B$ form an ideal solution. If $X_A$ and $Y_A$ are the mole fractions of $A$ in the solution and in vapour phase in equilibrium,respectively,then (Given $P_A^{\circ} > P_B^{\circ}$):