A manager is applying the transportation model of linear programming to solve an aggregate planning problem. Demand in period 1 is 325 units, in period 2 is 375 units and in period 3 is 425 units. The manager has 225 hours of regular employment available for $10/hour each period. In addition, 150 hours of overtime are available for $15/hour each period. The manager also has the option to subcontract the production at rate of $18/hour for the maximum of 50 hours. If holding cost is $1 per unit each period, what is the minimum production cost? Period Demand 1 325 2 375 3 425 Options Rate ($) Hours available 10 Regular time 225 Overtime 15 150 Subcontract 18 50