A carpentry company produces four types of tables. The company has two workshops. All products need first to go through the production workshop and then to the second workshop to be painted. Here is the amount of labor-hour required for each of the table types in either workshops: Workshop Table 1 Table 2 Table 3 Table 4 Production 4 9 7 10 Painting 1 1 3 4 For the next six months, the production workshop will have a maximum capacity of 6000 labor hours and the painting workshop will have 4000 labor-hours. The profit gained from each of these table types is: Table type Table 1 Table 2 Table 3 Table 4 Profit 12 20 18 40 Using a mathematical model, specify how many of each table types should be built so that the total profit becomes maximum?