1. When backorder is not allowed, add an appropriate constraint in the spreadsheet and find the optimal solution. Please include a snapshot of the constraint you add, list the optimal solution including the decision variables and corresponding minimized total cost. 2. Assuming that backorder is not allowed, add an appropriate constraint that forces the factory to maintain a minimum buffer inventory of 100 gears each month. Please include a snapshot of the constraint you add, list the optimal solution including the decision variables and corresponding minimized total cost