4. Alex and Jessica own two comee shops that supply coffee to the local university, Labor is their only variable input. Suppose the marginal product of labor in Shop A is MP 22 L where L is the number of workers allocated to Shop A. The marginal product of labor of Shop B is MP 20-Le, where La is the number of laborers assigned to Shop B. Suppose that Alex and Jessica employ a total of 10 workers. What is the best assignment of the 10 workers to the two shops?