A real-estate development firm is considering five development projects over a 3-year planning horizon. If a project is selected, it has to continue executing during the three years. The following table shows the estimated long-run profit (net present value) that each project would generate at the end of the planning horizon, as well as the yearly expenditures to undertake the projects, in millions of USD1:Development project(numbers are in millions)

	1	2	3	4	5
Expenditures year 1	6	12	10	4	8
Expenditures year 2	1	7	9	4	6
Expenditures year 3	8	10	2	1	10
Estimated profit	1	1.8	1.6	0.8	1.4

Also, project 1 requires that project 5 is selected too, i.e., project 5 can be selected without project 1, but the project 1 cannot be selected without the project 5. The owners of the firm have projected that the available funds are $20 million for year 1,$25 million for year 2, and $25 million for year 3. The firm wants to select the combination of projects that will maximize their total estimated long-run profit within the available funds.

1. Formulate a mathematical model for this problem (50 points).

2. Solve this problem utilizing Excel solver and provide the appropriate recommendations and expected profits (50 points)