Two liquids X and Y forms an ideal solution at 300K vapour pressure of the soluton containing 1 mol of X and 3 mol of Y is 550 mmHg. At the same temperature, if 1 mol of Y is further added to this solution, vapour pressure of the solution increases by 1 0 mm Hg. Vapour pressure (in mmHg) of X and Y in their pure states will be, respectively.

(1) 200 and 300

(2) 300 and 400

(3) 400 and 600

(4) 500 and 600