What is the model for this LP problem so to Minimize the production cost?

Metalco manufactures two types of steel at three different steel mills. Iron is the primary raw material used to make steel, and the amount available in any given month is 1500 tons. For any of the three mills, when iron is used to make steel 1, the yield is 0.20 tons of steel per ton of iron; Similarly, for steel 2, the yield is 0.65 tons of steel 2 per ton of iron. During a given month, each steel mill has 200 hours of blast furnace time available. Because of differences in the furnaces at each mill, the time and cost to produce a ton of steel differs for each mill. The time and cost for each mill are shown in the table below. Each month, Metalco must manufacture at least 500 tons of steel 1 and 600 tons of steel 2. Due to preference for steel 2 by customers, for every ton of steel 1, at least 1.5 tons of steel 2 should be produced. Producing a Ton of Steel Steel 1 Steel 2 Mill Cost Time Cost Tirne (Minutes) (Minutes) 1 $ 10 20 $ 11 22 $ 12 24 $ 14 25 {AN $14 28 $13 30