Office building maintenance plans call for the stripping, waxing, and buffing of ceramic floor tiles. This work is often contracted out to office maintenance firms, and both technology and labor requirements are very basic. Supply and demand conditions in this perfectly competitive service market in St. Paul, Minnesota, are: QS= -110 2P(Supply) QD= 150 - 6P(Demand) where Q is thousands of hours of floor reconditioning per month, and P is the price per hour.