Union Express has 60 tons of cargo that needs to be shipped from Boston to Dallas. The shipping capacity on each of the routes Union Express planes fly each night is shown in the following table:

Nightly Flight Segments Capacity (in tons)

Boston to Baltimore ..........30

Boston to Pittsburgh ..........25

Boston to Cincinnati ..........35

Baltimore to Atlanta ..........10

Baltimore to Cincinnati ......... 5

Pittsburgh to Atlanta ..........15

Pittsburgh to Chicago ..........20

Cincinnati to Chicago ..........15

Cincinnati to Memphis ......... 5

Atlanta to Memphis ..........25

Atlanta to Dallas ...........10

Chicago to Memphis ..........20

Chicago to Dallas ..........15

Memphis to Dallas ...........30

Memphis to Chicago .........15

Will Union Express be able to move all 60 tons from Boston to Dallas in one night?

a. Draw a network flow model for this problem.

b. Create a spreadsheet model for the problem and solve it.

c. What is the maximum flow for this network?