Pristine Aircraft Maintenance has received four Boeing 737 airplanes that require maintenance. Airplane SW-023 will require 4 days of hull inspection and 3 days of painting, Airplane DL-040 will require 1 day of hull inspection and 4 days of paint- ing, Airplane SA-009 will require 5 days of hull inspection and 1 day of painting, while Airplane AA-887 will require 5 days of hull inspection and 5 days of painting. (Hull inspection must always be completed before painting can begin.) Assume that Pristine Aircraft Maintenance uses Johnson's rule to minimize the overall time needed to complete maintenance on these four airplanes.

a. In what order will Pristine Aircraft Maintenance complete these three airplanes?

b. When should Pristine Aircraft tell each airplane owner that the airplane will be completed and available for flying?

c. When will Pristine Aircraft Maintenance be finished with all the work described in this scenario?