What is the total number of units to be assigned?

General Accounting

Apsara Beverages Co. uses process costing to account for the production of bottled sports drinks. Direct materials are added at the beginning of the process, and conversion costs are incurred uniformly throughout the process. Equivalent units have been calculated to be 21,600 units for materials and 18,000 units for conversion costs. Beginning inventory consisted of $13,500 in materials and $7,200 in conversion costs. May costs were $62,400 for materials and $72,000 for conversion costs. The ending inventory still in process was 7,000 units (100% complete for materials, 50% for conversion). The cost per equivalent unit for materials using the weighted-average method would be____.