Solutions: JEE Main 2022 Chemistry question

A gaseous mixture of two substances A and B, under a total pressure of $0.8$ atm is in equilibrium with an ideal liquid solution. The mole fraction of substance A is $0.5$ in the vapour phase and $0.2$ in the liquid phase. The vapour pressure of pure liquid $\mathrm{A}$ is __________ atm. (Nearest integer)