National Express reports the following costs and expenses in June 2020 for its delivery service. Indirect materials $7,100 Drivers' salaries $17,100 Depreciation on delivery equipment 12,100 Advertising 4,800 Dispatcher's salary 5,450 Delivery equipment repairs 470 Property taxes on office building 880 Office supplies 660 CEO's salary 12,900 Office utilities 1,040 Gas and oil for delivery trucks 3,000 Repairs on office equipment 220 Determine the total amount of (a) delivery service (product) costs and (b) period costs. Delivery service (product) costs Period costs $ $