Distance from factory i to factory j

1

2

3

4

Demand from factory i

1

4

12

20

6

100

2

2

10

25

10

50

3

3

4

16

14

120

4

6

5

9

2

80

5

18

12

7

3

200

6

14

4

4

9

70

7

20

30

2

11

60

8

24

12

6

22

100