(Answered) : The demand forecast for the next four periods is 90, 100, 120, and 140 units respectively. The plant has a regular capacity of 1

The demand forecast for the next four periods is 90, 100, 120, and 140 units respectively. The plant has a regular capacity of 100 units per period, an overtime capacity of 10 units per period, and a subcontractor capacity of 5 units per period. There is a $5 per unit charge for regular production, an $8 per unit charge for overtime production, and a $9 per unit charge for subcontracting. The holding cost is $3 per unit per period, no shortages are allowed and the company has 5 units in inventory at the start of the planning period?

a. How many