Please do not use excel.

Example 1: Minimize Cost A company has three production plants, each of which produces three different models of a particular product. The daily capacities (in thousands of units) of the three plants are as follows: Model Model 2 Model 3 Plaul 8 4 8 Plant 2 6 3 Plant 12 8 The total demand for Model 1 is 300,000 units, for Model 2 is 172,000 units, and for Model 3 is 249,500 units. Moreover, the daily operating cost for Plant 1 is $55,000, for Plant 2 is $60,000, and for Plant 3 is $60,000. How many days should each plant be operated in order to fill the total demand, and keep the operating cost at a minimum? How would you modify this problem if we don't want Model 3 to be produced in plant 3? How would you modify this problem if we want to guarantee that plant 1 operates at least 100 days