When two liquid $A$  and $ B$  are mixed then their boiling points becomes greater than both of them. What is the nature of this solution

Which of the following mixture shows positive deviation by ideal behaviour

If $x$ gram of non-volatile, non-electrolytic solute is dissolved in $114\  g$ octane to reduce its vapour pressure to $80\%$ of that of pure octane then $x$ is ……….. $g$. (Molar mass solute $= 40\  g/mole$)

A solution of two miscible liquids showing negative deviation from Raoult's law will have :

A mixture of liquid showing positive deviation in Raoult's law is