A connecting flight from Buffalo to Washington D.C. has a capacity of 9 seats. In that flight, there is one flight attendant providing on-board service to all customers. The flight time from Buffalo to Washington D.C. is one hour and twenty minutes, but overall available service time for this attendant is one hour (i.e., 60 minutes).

There are two types of customers. Full-fare customers are willing to pay $400 for each seat, and typically require 10 minutes of on-board services from this flight attendant. On the other hand, discount-fare customers pay $300 for each seat, but will require only 4 minutes of service time from this flight attendant. Suppose there are enough demand for both full-fare customers and discount-fare customers.

a. Using an LP model and solving it with Excel Solver to find the optimal numbers of customers, for each type, this airline will accept to maximize its revenue performance? (1.5 pts)

b. If the airline has to pay another attendant $450 for 30 more minutes service time (now a total of 1.5 hours), is it a good decision? Why? (1.5 pts)