Consider the capital budgeting problem where six projects are being considered for execution over the next 3 years. The expected returns for each project and the yearly expenditures (in thousands of dollars) are shown in the accompanying table. Assume that each approved project will be executed over the 3-year period. The objective is to select the projects that will maximize the total returns.

	Expenditures for
Project	Year 1	Year 2	Year 3	Returns
1	5	2	8	20
2	9	7	9	40
3	4	6	3	15
4	7	4	4	21
5	3	5	2	12
6	8	4	9	28
Max. available Funds	26	22	25

Formulate the problem as a linear programming problem with additional constraints on decision variables to be 0 or 1.