Cost of oils used to lubricate production machinery 2. Depreciation of factory plant and equipment 3. Cost of chemicals used in the laboratory 4. Commission paid to sales representatives 5. Salary of the secretary to the finance director 6. Trade discount given to customers 7. Holiday pay of machine operators 8. Salary of security guard in raw material warehouse 9. Rent of finished goods warehouse Reference numbers( ) are production costs. Reference numbers( ) are Selling and distribution costs Reference numbers( ) are Administration costs Reference numbers( ) are Research and development costs