Can someone explain the basic formula i need to use for this question?

The Work in Process Inventory account had a beginning balance of $16,200 on April 1. During April, the cost of direct materials used was $408,000 and direct labor cost assigned to production was $56,000. A total of $72,000 of overhead was assigned to production in April. If the cost of finished goods manufactured was $523,500, what was the balance in the Work in Process Inventory account on April 30?