SHOW ME HOW EE 20-2975 PE 20-2B Units to be assigned costs OBJ. 2 Blackrock Steel Company has two departments, Casting and Rolling. In the Rolling Depart- ment, ingots from the Casting Department are rolled into steel sheet. The Rolling Depart- ment received 13,900 tons from the Casting Department. During the period, the Rolling Department completed 12,700 tons, including 800 tons of work in process at the begin ning of the period. The ending work in process inventory was 2,000 tons. How many tons were started and completed by the Rolling Department during the period