Three departments are involved in the processing required for the products in a

manufacturing company. A summary of the material flow matrix $($between departments$)$

and distance matrix $($between sites, in feet$)$ can be found in the tables below. The material

handling cost is directly proportional to the distance travelled.

a$)$ Use a pairwise exchange method to determine the optimal solution. Suppose the initial

solution is given by $($A:$3,$ B: $1,C$:$2)($Note: calculate only $1$ iteration$)$

b$)$ Determine a lower bound by "ordering" method.