Reconsider the maximum flow problem shown in Prob. 9.5-6. Formulate this problem as a minimum cost flow problem, including adding the arc A → F. Use 
= 20.
Prob. 9.5-6
Consider the maximum flow problem shown next, where the source is node A, the sink is node F, and the arc capacities are the numbers shown next to these directed arcs.
(a) Use the augmenting path algorithm described in Sec. 9.5 to solve this problem.
(b) Formulate and solve a spreadsheet model for this problem.