please solve a , b with clear font

02/ 1000kg/h of an acetone - water mixture containing 20wt% by weight of acetone is to be counter currently extracted with trichloroethane. The recovered solvent to be used is free from acetone. The water and trichloroethane are insoluble. If 90% recovery of acetone is desired estimate the number of stages required if 1.5 times the minimum solvent is used. The kg acetone/kg extract=1.65 kg water/kg raffinate. a. Repeat the calculation of A if the solvent used has purity of 98.5%. b- If co-current extractor is used instead of counter-current extractor in A and B estimate the number stages required if equal amount of solvent used in each stage