A stirred tank (initial V = 100 liters) is used to grow cells. Given Y_X/S = 0.5 gX/gS, mu_m =0.18 day^-1 and S_0 = 3 gm/lit. The reactor is inoculated with 1.5 gm/lit of cells and operated until the substrate is virtually exhausted. Flow is initiated at 4 lit/day (S_0 = 3 gm/lit) and fed-batch operation is carried out for 40 days. a. Find the batch culture time and the final biomass concentration for the batch culture time. b. What is the final mass of cells in the reactor? c. Downtime between production processes is 24 hours. The fermenter is available 275 days per year. How much biomass is produced annually?