Pumpkin seeds with a composition of 31 % oil, 58 % solids and 11 % water by weight are used to make oil by cold-pressing. The cake coming out of the press expeller is found to contain 85 % solids and 3 % oil. Find the percentage recovery of oil (working with kg as units of operation) assuming that all water stays in the cake and the recovered pure oil is completely dry and free of solids and state your assumptions.