Consider again the Ohio Trust bank location problem discussed in Section $7\mathrm{.}3.$ The file

OhioTrustFull contains data for all of Ohio$$s $88$ counties. The file contains an $88388$

matrix with the rows and columns each being the $88$ counties. The entries in the matrix are

zeros and ones and indicate if the county of the row shares a border with the county of the

column $(15$ yes and $05$ no$).$

a$.$ Create a model to find the location of required principal places of business $($PPBs$)$ to

minimize the number of PPBs needed to open all counties to branches.

b$.$ Solve the model constructed in part $($a$).$ What is the minimum