Assume that producing 1 unit of coal requires 0.2 units of coal, 0.1 units of lumber, and 0.1 units of steel; that producing 1 unit of lumber requires 0.2 units of coal, 0.1 units of lumber, and 1.3 units of steel; and that producing 1 unit of steel requires 0.7 units of coal, 0 units of lumber, and 0.1 units of steel.
Find the production schedule that satisfies an external demand for 57 units of coal, 26 units of lumber, and 10 units of steel.
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