expected to remain stable at $12 per unit for the next 12 periods, and no quantity discounts are available. The maximum order size is 1,000 units. the end of period t, and Yt={1ifanorderisplacedatthestartofperiodtfort=1,2,3,,12.0otherwise ) Min()(x1+x2++x12)+()(H1+H2++H12)+(1)(Y1+Y2++Y12) Period 1 Demand Period 2 Demand Period 3 Demand Period 4 Demand Period 5 Demand Period 6 Demand Period 7 Demand Period 8 Demand Period 9 Demand Period 10 Demand Period 11 Demand Period 12 Demand xt()Ytfort=1,2,3,,12xtHt0,fort=1,2,3,,12Yt=0,1,fort=1,2,3,,12 (b) Solve the model formulated in part (a). What is the optimal cost (in $ )? How many orders are placed? orders