Four water use entities (users 1−4) are to be supplied from one or more of four pos­sible...

Four water use entities (users 1−4) are to be supplied from one or more of four pos­sible sources (A−D). Sources A, B, and C cost $21,000,000, $38,000,000, and $30,000,000, respectively, to develop. Source D costs only $12,000,000 to develop, but can only supply customer 3. Sources C and D are mutually exclusive, meaning either, but not both, may be selected. One, two, or three water supply sources may be de­veloped and used. A pipeline must be constructed from each of the four customers to at least one of the four water supply sources. A source is developed only if at least one customer's pipeline is constructed to it. Costs for constructing the four pipelines to the customers are provided below.

Each of the four customers are to be supplied from one of the four possible The problem is to decide: (1) which source(s) to develop and (2) if more than one is developed, which source will supply each customer. Use zero-one LP to determine which water supply sources to develop and which pipelines to construct in order minimize total costs (costs of developing sources plus cost of constructing 4 pipelines)