Oahu Kiki tracks the number of units purchased and sold throughout each accounting period but applies its inventory costing method at the end of each month, as if it uses a periodic inventory system. Assume Oahu Kiki’s records show the following for the month of January. Sales totaled 310 units.

Date Units Unit Cost Total Cost
Beginning Inventory January 1 220 80 $17,600
Purchase January 15 310 90 27,900
purchase January 24 270 110 29,700

Calculate the number and cost of goods available for sale.