*Please solve all questions clearly*

Fast-food restaurants like McDonalds are replacing cashiers with touch-screen ordering kiosks. Currently, the marginal product of another cashier is 48 customers served per hour; the marginal product of another kiosk is 32 customers served per hour. A cashier can be hired for a wage of $15; a kiosk rents for $12.

a. What is the marginal product of labor per dollar?

MPL/W= ?

b. What is the marginal product of a kiosk per dollar?

MPK/R= ?

c. Is McDonalds currently minimizing the cost of serving its customers? Why?

, because MPLW is MPKR.