Again, I know I keep posting questions but I'm begging you for help.

At 25°C the vapour pressure of pure pentane is 511 torr and that of hexane is 150. torr.
What is the mole fraction of pentane in a pentane-hexane solution that has a vapour pressure of 339 torr at 25°C?

What is the mole fraction of hexane in the vapour that is in equilibrium with this solution?
(Assume ideal gas behaviour.)