Hadley, Incorporated, manufactures a product that uses $$15$ in direct materials and $$5$ in direct labor per unit. Under the traditional costing system Hadley uses, manufacturing overhead applied to each unit is $$12.$ However, Hadley is considering switching to an ABC system. Under the ABC system, the total activity cost would be $$25.$ What is the total manufacturing cost per unit for Hadley under the ABC system?