Capital budgeting using integer optimization

please build an excel model for this question

A company has 6 potential projects and a limited capital budget over the next several years. They want to maximize the expected NPV from the projects. That is, they want to determine the optimal project portfolio. Data is provided in the spreadsheet file for years 0 (now) through year 5 for 6 projects. The discount rate is 5%. Dollar values are in $ millions. The NPV of each project has already been calculated, but you can verify they are correct. The capital budget limit for time 0 (now) is $45M; for year 1 is $30M; and for year 2 is $20M. No capital budget is available for this set of projects in years 35, so whatever portfolio of projects is selected, the porfolio as a whole needs to be self-sustaining after year 2 . Capital funds cannot be carried over from one year to the next. Algebraic Formulation Highly recommended. Write out the algebraic formulation of the problem, including decision variables. Use Pi to represent whether Project i is selected or not. When you do this, keep the cash flows as they are in the spreadsheet, i.e., negative for negative cash flows and vice versa. Then, the most direct way to model the constraints is to negate the entire left-hand-side of your constraint, and set that to be