A town operates two recycling centers. Each day that Center I is open, 300 lbs. of glass, 200 lbs. of paper, and 100 lbs. of aluminum are deposited there. Each day that Center II is open, 100 lbs.
of glass, 600 lbs. of paper, and 100 lbs. of aluminum are deposited there. The town has
contracted to supply at least 1200 lbs. of glass, 2400 lbs. of paper, and 800 lbs. of aluminum per
week to a salvage company. Supervision and maintenance at Center I costs $40 each day it is
open, and Center II costs $50 each it is open. How many days a week should each center remain
open so as to minimize the total weekly cost for supervision and maintenance, yet allow the
town to fulfill its contract with the salvage company?