Sepulveda Corporation uses a process costing system to manufacture laptop PCs. The following information summarizes operations for its VeryLite model during the quarter ending March 31, Year 1: Units Direct Materials Work-in-process inventory, January 1 100 $ 60,000 Started during the quarter 500 Completed during the quarter 400 Work-in-process inventory, March 31 200 Costs added during the quarter $840,000 Beginning work-in-process inventory was 50% complete for direct materials. Ending work-in-process inventory was 75% complete for direct materials. What were the equivalent units for direct materials for the quarter using the FIFO method?

1. 450 2. 500 3. 550 4. 600

please show me every calculation