Problem
Professor teaches two sections Management Science, which combined will result in 130 final exams to be graded. Professor Matthews has two graduate assistants (TAs), James and Ann, who will grade the final exam. There is a three-day period between the time the exam is administered and when the final grades must be posted by the Registrar at Algoma University. During this period James has 14 hours available and Ann has 12 hours available to grade the exams. It takes James on average 8.4 minutes to grade an exam, and it takes Ann 15 minutes to grade an exam however James exams will have errors that will require Professor Matthews to ultimately regrade 12% of his exams while only 5% of Ann's exams will require regarding. Professor Matthews wants to know how many exams to assign to each TA to get all of them graded but he also wants to minimize the number of exams that he will be required to regarded.
Task
i. Formulate a LP model for this problem and solve this model using Excel.
ii. If Professor Matthews could hire James or Ann to work one more hour, who should he choose? What would be the effect of hiring the selected TA for one additional hour?