Pyramids Industries has estimated the aggregate demand , cost , and production data for the next six months as follows : Cost Data Hiring cost/worker $ 200.00 Layoff cost/worker $ 100.00 Regular time cost/hour $7.00 Holding cost/unit/month $8.00 Overtime cost/hour $ 11.00 Production D Working hours/month 160 Labour hours/unit Beginning Inventory 250 Beginning Workforce 20 Planning horizon 6 months) Monthly Demand Data May 500 June 700 July 1,200 Aug . 1,300 Sept. 900 Oct. 800 Develop three aggregate production s schedules to : i) Produce exactly enough units to satisfy the demand each month using regular time by varying g the size of the workforce . What is the overall cost ? ii Produce using current workforce size on regular time and vary inventory levels to absorb changes in demand . What is the overall cost ? iii ) Produce using current workforce size . Use overtime to meet additional output requirements not satisfied by regular time production in a given month . However overtime production in a given month cannot exceed 15% of the regular time production What is the overall cost ? iv ) Assume that hiring -layoff , regular time , overtime and inventory carrying options are available and restriction on overtime production holds . Develop a linear programming model assuming that ending inventory for October must be at least 80 units . (Solver solution is not required )