Water is to be used in a single equilibrium stage to dissolve 1,350 kg/h of Na2CO3 from 3,750 kg/h of a solid, where the balance is an insoluble oxide. If 4,000 kg/h of water is used and the underflow from the stage is 40 wt% solvent on a solute-free basis, compute the flow rates and compositions of the overflow and the underflow.