Chemistry help! mole fractions!?

You have a flask containing 350.0 mL of air at a pressure of 1 atm and 50.0 mL of a very cold liquid. Because the liquid is cold, none of this liquid is present in the gas phase; the flask contains only air. The flask is sealed and allowed to warm to 273 K where the liquid vaporizes to form an equilibrium mixture and you note that the pressure in the flask has increased to 1.34 atm. You determine that the partial pressure of the vapor from the liquid is 0.100 atm; calculate the mole fraction of the vapor from the liquid in the air-vapor mixture in the flask.