Tigris produces only two products: tennis balls and tennis racquets. Each worker comes with a fixed quantity of materials and capital, and the economy's labour force is fixed at 100 workers. The following table indicates the amounts of balls and racquets that can be produced daily with various quantities of labour: Number of Workers Daily Production of Number of Workers Daily Production of Tennis Balls Racquets 0 20 80 100 0 80 150 200 230 250 0 20 40 60 80 100 a) Can Tigris produce 200 balls and 60 racquets? b) What is the total cost of producing 150 balls? c) What is the total cost of producing 75 racquets? 0 30 50 65 75 80 d) If Tigris is currently producing 230 balls, what is the cost of an additional 20 balls? e) If Tigris is currently producing 30 racquets, what is the cost of an additional 20 racquets?