The debits to Work in Process-Assembly Department for May, together with data conceming production, are as follows: May 1, work in process Materials cost, 3,000 units Conversion costs, 3,000 units, 50% completed Materials added during May, 10,000 units Conversion costs during May Goods finished during May, 11,500 units May 31 work in process, 1,500 units, 50% completed $7,200 5,700 25,900 31,900 0 0 All direct materials are placed in process at the beginning of the process, and the first-in, first-out method is used to cost inventories. The materials cost per equivalent unit for May is O $2.25 b. $2.59 Oc. $3.91 Od. 53.19