Problem $3.$ A medical facility's demand for N$95$ respirators and disposable gloves is deterministic and stable at a rate of $20$ respirators per day and $100$ gloves per day. The distributor charges $$20$ per pack of $20$ respirators and $$10$ for a pack of $25$ gloves. The distributor offered the healthcare facility the following plan: whenever the medical facility places a single order for both N$95$ respirators and gloves, the distributor will package one pack of respirators together with two packs of gloves to minimize shipping volume. The remainder of the order of gloves will be sent in the second shipment $($without any extra shipping cost$),$ which will be timed so that the healthcare facility receives the second shipment just before it runs out of gloves inventory. The shortages are not allowed. The fixed cost of placing an order is $$10$ and the holding cost rate is a $20\%$ annual interest rate $($assume $365$ days per year$).D_t=20$ respirators, $100$ gloves