Math 484.1.  November 3, 2011.   Midterm 2.  
5 problems, 15 pts each. \Write your name here ____________________________  and on the other side.
Write down how you got your answer.

1 Solve the linear program where all xi ≥ 0:

x1

x2

-2

-x4

 

 1

-2

3

 4

= x3

 1

2

1

 -3

= -x2

 2

2

-3

 0

--> max

 
2. Check whether   x1 = 0, x2 =0, x3 =4/ 3, x4 = 5/2, x5 = 0, x6 =0, x7 =6,
x8 = 0 is an optimal solution for the LP written in a standard tableau:

x1

x2

x3

x4

x5

1

 

1

-2

3

-4

5

6

= x6

-1

2

-3

4

-5

0

= x7

2

1

0

2

1

-5

= x8

2

0

1

-1

3

1

-> min


3-4. Solve transportation problems:

2

1

3

2

1

2

1

2

1

9

1

2

3

1

1

1

1

3

1

8

2

2

1

3

1

1

3

1

2

9

1

1

1

1

2

1

2

3

4

8

6

1

6

1

6

1

6

1

6

dem \ sup

 

3

1

3

2

1

2

1

2

1

9

1

1

3

1

1

1

1

3

1

8

2

2

1

3

1

1

3

1

2

9

2

3

1

1

2

1

2

1

2

8

6

1

6

1

6

1

6

1

6

dem \ sup


5. Solve job assignment problem

1

2

3

4

2

2

3

0

1

2

3

2

1

3

1

1

3

0

5

1

1

5

2

1

0