Taxes R Us (TRU), an income tax preparation firm, uses the FIFO method of process costing for its monthly reports. TRU has no materials cost in the preparation of the returns. The following shows its March information: Returns in process, March 1 (30% complete) Returns started in March Returns in process, March 31 (90% complete) Labor and overhead costs for returns in process, March 1 Labor and overhead costs incurred in March 140 1,800 280 $ 3,500 $121,550 Required: Calculate the following amounts for conversion costs using the FIFO method: + 2 Number of equivalent units (tax returns) Cost per equivalent unit Cost of completod tax returns for the month of March Cost of tax returns in process as of March 31 3 4