What are the compositions of the equilibrated top Layers?

Figure is a temperature-composition phase diagram for the binary system of water (A) and phenol (B) at 1 bar. These liquids are partially miscible below 67°C. Phenol is more dense than water, so the layer with the higher mole fraction of phenol is the bottom layer. Suppose you place 4.0mol of H₂O and 1.0mol of phenol in a beaker at 30°C and gently stir to allow the layers to equilibrate.

(a) What are the compositions of the equilibrated top and bottom layers?

(b) Find the amount of each component in the bottom layer.

(c) As you gradually stir more phenol into the beaker, maintaining the temperature at 30°C, what changes occur in the volumes and compositions of the two layers? Assuming that one layer eventually disappears, what additional amount of phenol is needed to cause this to happen?