JEE Advanced 2018 · Paper 1, Chemistry question 12

Liquids A and B form ideal solution over the entire range of composition. At temperature T, equimolar binary solution of liquids A and B has vapour pressure 45 Torr. At the same temperature, a new solution of A and B having mole fractions $x_A$ and $x_B$, respectively, has vapour pressure of 22.5 Torr. The value of $x_A/x_B$ in the new solution is ______.

(given that the vapour pressure of pure liquid A is 20 Torr at temperature T)