plz solve it without using excel

An industrial engineer has forecasted the following demands for product X as a first step to develop a production plan Month Demand 1 900 2 3 1000 760 4 900 5 6 1000 1200 Each unit of product X requires 4 worker-hour to produce. The workforce at the beginning of the month was 25 workers. There are 20 working days per month and each worker works 8-hour day. Labor cost is AED 30 per hour and inventory holding cost is AED 5 per unit per month. The hiring cost is AED 2000 per worker and the firing cost is AED 3000 per worker. May 1000 June 1200 Total 5760 a- Vary the workforce to meel exactly the demand Month Jan Feb Mar Apr Demand 900 1000 760 900 # workers Production Inventory Hiring Firing b- Produce at constant rate over the planning horizon Jan 900 Feb 1000 Mar 760 Apr 900 May 1000 June 1200 Total 5760 Month Demand #workers Production Inventory