The Property Manager of a City Government Issues Chairs,desks,and Other

The property manager of a city government issues chairs,desks,and other office furniture to city buildings from a centralized distribution center.Like most government agencies,it operates to minimize its costs of operations.In this distribution center,there are two types of standard office chairs,Model A and Model B.Model A is considerably heavier than Model B,and costs $20 per chair to transport to any city building;each model B costs $14 to transport.The distribution center has on hand 400 chairs-200 each of A and B.
The requirements for shipments to each of the city's buildings are as follows:
Building 1 needs at least 100 of A
Building 2 needs at least 150 of B.
Building 3 needs at least 100 chairs,but they can be of either type,mixed.
Building 4 needs 40 chairs,but at least as many B as A.
Formulate this problem as a linear program.(Hint: there are eight decision variables because we need to know how many of each chair (A and B)to deliver to each of the four buildings).