Two proteins A and B are being fractionated from an aqueous feed solution by ultrafiltration. At the cross-flow velocity being used the mass transfer coefficient of A is 4 x 10^-6 m/s while that of B is 8 x 10^-6 m/s. The fractionation is being carried out at a constant permeate flux of 1 x 10^-6 m/s. The permeate flux and mass transfer coefficients combination is known to result in intrinsic sieving coefficients of 0.1 and 0.5 for A and B respectively. If we assume that each protein behaves independently of the other, predict the selectivity of separation. If the concentrations of A and B in the solution are 1 kg/m³ and 3 kg/m³ respectively, predict the composition of the permeate.