Globex Investment Capital Corporation owns six companies that have the following estimated returns (in millions of dollars) if sold in one of the next 3 years:

Year Sold

(estimated return, $1,000,000s)

Company 1 2 3 1 $14 $18 $23 2 9 11 15 3 18 23 27 4 16 21 25 5 12 16 22 6 21 23 28 To operating funds, the company must sell at least $20 million worth of assets in year 1, $25 million in year 2, and $35 million in year 3.

Globex wants to develop a plan for selling these companies during the next 3 years to maximize return.

Formulate an integer programming model for this problem, and solve it by using the computer.