We have 5 projects for execution over the next 3 years. The expected return for each project and funds needed and available each year (in thousands dollars) are given as follows:

Year 1

Year 2

Year 3

Return

Project 1

5

1

8

20

Project 2

4

7

10

40

Project 3

3

9

2

20

Project 4

7

4

1

15

Project 5

8

6

10

30

Funds available

25

24

23

Which of the five projects should be executed over the three years knowing that

a)Exactly two of the projects 3 , 4 and 5 must be done.

b)If project 1 and 3 are done project 5 must be done.

c)Project 1 and 2 must be undertaken simultaneously.

Formulate a linear programming which maximize the return. (setup and do not solve)