If your new strip mall will have 15,000 square feet of retail space available to be leased, to which ...

Business Name   Square Feet Required   Expected Monthly Cash Flow   C/F per S.F.   Project Rank
Videos Now   4000   70,000   17.5   5
Gords Gym   3500   52,500   15   7
Pizza Warehouse   2500   52,500   21   3
Super Clips   1500   25,500   17   6
30 1/2 Flavors   1500   28,500   19   4
S-Mart    12,000   180,000   15   8
WalVerde Drugs   6000   147,000   24.5   1
Multigular Wireless   1000   22,250   22.25   2

So we select projects based upon their ranking until we run out of space.  The optimal combination is shown below:

WalVerde Drugs   6000   147,000   24.5   1
Multigular Wireless   1000   22,250   22.25   2
Pizza Warehouse   2500   52,500   21   3
30 1/2 Flavors   1500   28,500   19   4
Videos Now   4000   70,000   17.5   5
Total   15,000   $320,250