Sony, a television company, has three major departments for the manufacture of its two models, A and B. The monthly capacities are given as follows: the marginal profit per unit from model A is birr 400 and that of model B is birr 1000. Assuming that company can sell any quantity of either product due to favorable market conditions, determine the optimum output for both the models, the highest possible profit for this month and the slack time in the three departments.