$4.$ Your third$-$party warehouse has space available for $10,000$ pallets and you have $20$ forklift operators per $8-$hour day for $250$ working days a year. If the average trip from receiving to storage to shipping is $10$ minutes per pallet, how many inventory turns a year could you support for a full warehouse?

Warehouse inventory turns at the rate of two times per month. One thousand dollars$$ worth of merchandise occupies $100$ cubic feet of warehouse space and can be stacked $10$ ft$.$ high. The product density is $$5$ per lb$.$ Given aisles, administrative space, and normal operating efficiency, only $40$ percent of the total warehouse space is actually used for storage.

A private warehouse can be constructed and equipped for $$35$ per sq$.$ ft$.$ and can be amortized over $20$ years. The cost of operation is $$20$ for one thousand dollars$$ worth of throughput. Annual fixed costs amount to $$10$ per sq$.$ ft$.$ of total space.

Space can also be rented for a storage charge on inventory of $$0\mathrm{.}06$ per lb per month and handling charge of $$0\mathrm{.}05$ per lb of throughput.

$($Hint: Use density to change a $ unit into a lb unit if required$)$