computing spreadsheet help

1. State University must purchase 1700 computers from three vendors.
Vendor 1 charges $500 per computer plus a total delivery charge of $5,000.
Vendor 2 charges $350 per computer plus a total delivery charge of $4,000.
Vendor 3 charges $250 per computer plus a total delivery charge of $6,000.
Vendor 1 will sell the university at most +600 computers, vendor 2, at most
1100, and vendor 3, at most 700. The minimum order from a vendor is
200 computers. Determine how to minimize the cost of purchasing the
needed computers.
a. Interpretation “a” – Each vendor must supply at least the
minimum. Hence all vendors are used and all delivery charges are
incurred.
b. Interpretation “b” – Each vendor must supply at least the
minimum only if that vendor is used. Hence delivery charges are
incurred only for those vendors used. Hint – A fixed cost can be
modeled by using a binary integer variable.