There is no spoilage, the beginning work-in-process inventory is 6,000 units, and the ending work-in-process inventory is

Question:

There is no spoilage, the beginning work-in-process inventory is 6,000 units, and the ending work-in-process inventory is 4,000 units for the second department in a two department process. What is the number of units transferred in to the second department if good output of the second department is 35,000 units?