Which of the following will form an ideal solution?

What is a non-ideal solution and what is meant by positive deviation from Raoult's law?

$A$ mixture of benzene and toluene forms

Assuming the formation of an ideal solution,determine the boiling point of a mixture containing $1560 \ g$ benzene (molar mass $= 78 \ g/mol$) and $1125 \ g$ chlorobenzene (molar mass $= 112.5 \ g/mol$) against an external pressure of $1000 \ torr$. Use the provided vapor pressure vs. temperature graph to find the answer. (in $^{\circ}C$)

$5$ moles of liquid $X$ and $10$ moles of liquid $Y$ make a solution having a vapour pressure of $70 \ torr$. The vapour pressures of pure $X$ and $Y$ are $63 \ torr$ and $78 \ torr$ respectively. Which of the following is true regarding the described solution?

Each pair forms an ideal solution except?