Question $4$

$[8]$

a$.$ Find a maximum flow from source $($node $r)$ to sink $($node $s)$ in the digraph. Describe each step clearly with a diagram.

b$.$ Describe the problem as a linear programming problem.

c$.$ Verify the truth of the Max$-$Flow Min$-$Cut Theorem for the network flow which you found in $($a$).$