30) A water company is analyzing the flow of water through pipes in an office building.
The flow capacities are given in the table below. Flow is measured in 100 gallons/hour.
What is the maximal flow of water from node 1 to node 5?
31) A package express carrier is considering expanding the fleet of aircraft used to
transport packages. There is a total of $220 million allocated for purchases. Two types
of aircraft may be purchased – the C1A and the C1B. The C1A costs $25 million, while
the C1B costs $18 million. The C1A can carry 60,000 pounds of packages, while the
C1B can only carry 40,000 pounds of packages. The company needs at least eight new
aircraft. In addition, the firm wishes to purchase at least twice as many C1Bs as C1As.
Formulate this as an integer programming problem to maximize the number of pounds
that may be carried.
32) Ivana Miracle wishes to invest up to her full inheritance of $300,000, and her goal
is to minimize her risk subject to an expected annual return of at least $30,000. She has
decided to invest her money in any of three possible waysCDs, which pay a guaranteed
6 percent; stocks, which have an expected return of 15 percent; and a money market
mutual fund, which is expected to return 8 percent. Risk factors are 1.0 for the CDs, 3.6
for the stocks, and 1.8 for the money market fund. What is the optimal solution and
minimum risk value?