4. (15) A firm operates a distribution center with the layout shown below. Pallets are received. Approximately 20% of pallets are cross docked. The remainder are stored in bulk storage (B). Cases are taken from pallets in (B) to replenish case storage in (C). Items are picked from case picking (C) and sent to sorting (T), then to packing (P), staging (G) and finally shipping (S). Selected material flows per month are shown between departments. a. () How many pallets are shipped out per month? b. (10) What is the monthly one-way distance for replenishment trips made from bulk storage to case picking