how to solve number 2?

1. The following mass and solute concentrations are given for an ideal single-stage extraction system: F=600kg;xF=0.36;S=720kg;xS=0. The amount and concentration of the extract are E=680kg and yE=0.28. What is the distribution coefficient K of the solute at the condition of the mixer-settler? K=7 2. Two hundred kilograms of a 40% solution of A in B (feed solvent) is equilibrated with 160kg of solvent S containing 3% of A. At equilibrium, the raffinate phase has a mass of 127kg and has 67%B and 9%S in it. What is the selectivity or separation factor of A ? =4.3438