The roniger company produce two products: bed mattresses and box springs. a prior contract requires that the firm produce at least 30 mattresses or box spring in any combination. in addition union labor agreements demands that stitching machines be kept running at least 40 hiurs per week which is one production period. each box spring takes 2 hours of stitching time, and each mattress takes 1 hour on the machine. each mattress produce cost $20; each box spring cost $24. formulate this problem so as to minimize total production cost.solve using the simplex method.