2. A post office requires different numbers of full-time employees on different days of the week. The number of full-time employees required on each day is given in the table below. Union rules state that each full-time employee must work five consecutive days and then receive two days off. For example, an employee who works Monday to Friday must be off on Saturday and Sunday. The post office wants to meet its daily requirements using only full-time employees. Formulate a model that the post office can use to minimize the number of full-time employees that must be hired. Number of Full-time Employees Required Day 1 = Monday Day 2 = Tuesday Day 3 = Wednesday Day 4 = Thursday Day 5 = Friday Day 6 = Saturday Day 7 = Sunday 17 13 15 19 14 16 11 3. In the post office problem above, suppose that each full-time employee works 8 hours per day. Thus, Monday's requirement of 17 workers may be viewed as a requirement of 8(17) = 136 hours. The post office may meet its daily labor requirements by using both full-time and part-time employees. During each week, a full-time employee works 8 hours a day for five consecutive days, and a part-time employee works 4 hours a day for five consecutive days. A full-time employee costs the post office $15 per hour, whereas a part-time employee (with reduced fringe benefits) costs the post office only $10 per hour. Union requirements limit part-time labor to 25% of weekly labor requirements. Formulate a model to minimize the post office's weekly labor costs.