[kankerfist]

I have a Txy diagram of Benzene and Toluene that shows the mole fraction of Benzene in the liquid phase and vapor phase for a range of temperatures at 1 atm.  I've been given the following information:

a system containing a 50 mole liquid mixture of 15 mole% benzene and 85 mole % toluene is initially 25 degrees Celsius and 1 atm.  The mixture is heated at constant pressure until it is 106 degrees Celsius and allowed to equilibrate.

I can see from my Txy diagram that when the temperature is 106 degrees Celsius, then:
Vapor is 25 mole% Benzene and 75 mole% Toluene
Liquid is 10 mole % Benzene and 90 mole% Toluene

What I am unsure about is how to use the diagram to also determine how many moles remain liquid after equilibrium.  I found the mole fraction in the remaining liquid, but that's all.  I know how to find it using Raoult's law and a physical property table, but I was wondering if there was a quicker way to find out just by using the Txy diagram.  If it's possible, any tips would be appreciated!  I need to learn as many time savers as possible for my upcoming test.