PLEASE SHOW THE EQUATIONS USED IN EXCEL FOR LIKE The blood bank wants to determine the least expensive way to transport available blood donations from Pittsburgh and Staunton to hospitals in Charleston, Roanoke, Richmond, Norfolk, and Suffolk. The supply and demand for donated blood is shown in the figure below along with the unit cost of shipping along each possible arc. Figure: Network flow model for the blood bank problem $1.$ Identify the supply, demand, and transshipment nodes in this problem. $2.$ Create a spreadsheet model for this problem. $3.$ What is the optimal solution? the solution is not clear and the spreadsheet model points are not clear