7 A fast-food restaurant serves hamburgers, cheeseburgers, and chicken sandwiches. The restau- rant counts a cheeseburger as equivalent to 1.25 hamburgers and chicken sandwiches as 0.8 ham- burger. Current employment is five full-time employees who work a 40-hour week. If the restaurant sold 700 hamburgers, 900 cheeseburgers, and 500 chicken sandwiches in one week, what is its productivity? What would its productivity have been if it had sold the same number of sandwiches (2,100) but the mix was 700 of each type?