Electrical Network

A power company, located in Philadelphia, wants to supply power to New York, Boston and Washington D.C. The power company can generate 10 kw/hour and the demands for the three cities are 2, 3, and 5 kw/h respectively. The power grid contains wires between some of the pairs of cities. Each wire has a cost, representing the cost of transmitting one kw/h over that wire, and a capacity, which limits the number of kw that travel over the wire per hour. The data appears below. Formulate a plan for the power company to supply power at the minimum possible cost.
Cities Cost Capacity
Philadelphia - New York $1 10
Philadelphia - Boston $6 10
New York - Boston $2 2
New York - Washington $7 3
Boston - Washington $4 5