Shelley is a furniture reseller. One of her biggest selling products is a wooden bookshelf that comes in two sizes big and small. The small shelves cost $300 and the big shelves cost $200 more than the small shelves. Each of the big shelves needs 100 cubic feet of storage space while the small shelves only need 90% of the storage space needed for the big shelves. Shelley has 18,000 cubic feet available for storage and her manager told her that she could spend $75,000 for the shelves this week. The profit for each big shelf is $300 and the profit for the small shelf is half of this amount. Required:
In the optimal solution, the total cubic feet of storage space that would be used for the big shelves is: