The Roniger Company produces two products: bed mattresses and box springs. A prior contract requires that the firm produce at least 30 mattresses or box springs, in any combination. In addition, union labor agreements demand that stitching machines be kept running at least 40 hours 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 produced costs $20; each box spring costs $24.

(a) Formulate this problem so as to minimize total production costs.

(b) Solve using the simplex method.