Which pair from the following will not form an ideal solution?

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 $bar$?

$A$ mixture of toluene and benzene boils at $100^{\circ} C$. Assuming ideal behaviour,the mole fraction of toluene in the mixture is closest to (Vapour pressures of pure toluene and pure benzene at $100^{\circ} C$ are $0.742 \ bar$ and $1.800 \ bar$,respectively. $1 \ atm = 1.013 \ bar$)

The vapour pressures of chloroform $(CHCl_3)$ and dichloromethane $(CH_2Cl_2)$ at $298 \ K$ are $200 \ mmHg$ and $415 \ mmHg$,respectively. An ideal solution is prepared by mixing $59.75 \ g$ of $CHCl_3$ and $21.25 \ g$ of $CH_2Cl_2$. The mole fractions of chloroform and dichloromethane in the vapour phase,respectively,are:

$A$ solution of two liquids boils at a temperature higher than the boiling point of either of them. Hence,the binary solution shows:

In a binary ideal solution of liquids $A$ and $B$ at a constant temperature,the mole fraction of $B$ in the liquid phase is $0.4$ and in the vapor phase is $0.25$. If $P_B^o = 40 \ mm \ Hg$,then the vapor pressure of pure liquid $A$ at that temperature is .......... $mm \ Hg$.