There is one problem to be solved. Define your decision variables clearly. You are not required to submit any answer report or sensitivity report for any question.

Emergency room of a hospital is open 24 hours a day. Nurses are either full-time or part-time and paid the same per hour. They can work in 6 different shifts; full-time nurses work 2 consecutive shifts (8 hours) and part-time nurses work a 4-hour shift. In each shift, the number of part-time nurses should be at least 20% of the number of full-time nurses to alleviate their workload. The following table shows the minimum number of nurses needed during each shift. How should the hospital schedule the nurses to minimize the total staff hired?

Shift timings	Minimum number of nurses required
1:00-5:00	12
5:00-9:00	12
9:00-13:00	18
13:00-17:00	12
17:00-21:00	16
21:00-1:00	6

Formulate an LP model first, then provide an excel solution.