Which pair of liquids shows positive deviation from Raoult's law?

On mixing,heptane and octane form an ideal solution. At $373 \ K$,the vapour pressures of the two liquid components (heptane and octane) are $105 \ kPa$ and $45 \ kPa$ respectively. Vapour pressure of the solution obtained by mixing $25.0 \ g$ of heptane and $35 \ g$ of octane will be $........ \ kPa$.
(molar mass of heptane $= 100 \ g \ mol^{-1}$ and of octane $= 114 \ g \ mol^{-1}$)

$A$ mixture of toluene and benzene forms a nearly ideal solution. Assume $p_{B}^{\circ}$ and $p_{T}^{\circ}$ to be the vapour pressures of pure benzene and toluene,respectively. The slope of the line obtained by plotting the total vapour pressure versus the mole fraction of benzene is $....$

Liquids $A$ and $B$ form an ideal solution. At $30\,^oC$,the total vapour pressure of a solution containing $1\,mol$ of $A$ and $2\,mol$ of $B$ is $250\,mm\,Hg$. The total vapour pressure becomes $300\,mm\,Hg$ when $1$ more $mol$ of $A$ is added to the first solution. The vapour pressures of pure $A$ and $B$ at the same temperature are

Liquids $A$ and $B$ form an ideal solution. Which of the following statements is true?

If liquids $A$ and $B$ form an ideal solution,which of the following statements is true?