Assume Anderson$$s General Store bought, on credit, a truckload of merchandise from American Wholesaling costing $$23,700.$ If Anderson$$s paid National Trucking $$720$ cash for transportation, immediately returned goods to American Wholesaling costing $$1,300,$ and then paid American Wholesaling within the $3/30,$ n$/60$ purchase discount period.

How much did this inventory cost Anderson$$s$?$ Assume Anderson$$s uses a perpetual inventory system.