Health Care Systems of Florida $($HCSF$)$ is planning to build a number of new emer$-$

gency$-$care clinics in central Florida. HCSF management has divided a map of the

area into seven regions. They want to locate the emergency centers so that all seven

regions will be conveniently served by at least one facility. Five possible sites are

available for constructing the new facilities. The regions that can be served conve$-$

niently by each site are indicated by $x$ in the following table:

Possible Building Sites

a$.$ Formulate an ILP problem to determine which sites should be selected in order

to provide convenient service to all locations in the least costly manner.

b$.$ Implement your model in a spreadsheet and solve it$.$

c$.$ What is the optimal solution?