property, manager of a city govm'nt issues chairs,desks and other office furniture to city buildings from a centralized distribution center.like most gov'mt. agencies it operates to minimize cost of operations. in this distribution center,there are two types of office chairs, model A and model B. model A is considerably heavier than model B, and cost $20 per chair to transport to any city building, each model B cost $14 to transport. the distribution center has on hand 400 chairs- 200 each of A and B. the requirements for shipments to each city building are follows:

building1 needs at least 100 of A

building2 needs at least 150 of B

building3 needs at least 100 chairs, but they can be of either type, mixed.

building4 needs 40 chairs, but atleast as many B as A.

write the objective function and constraints. HINT there are8 variables- chairs for building1 cannot be used to satisfy the demands for another building.