Which condition is not satisfied by an ideal solution?

Which one of the following is incorrect for an ideal solution?

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:

Which of the following will form an ideal solution?

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 $P_A^{\circ} > P_B^{\circ}$):

Formation of a solution from two components can be considered as
$(i)$ Pure solvent $\to$ separated solvent molecules $\Delta H_1$
$(ii)$ Pure solute $\to$ separated solute molecules $\Delta H_2$
$(iii)$ Separated solvent and solute molecules $\to$ solution $\Delta H_3$
Solution so formed will be ideal if