Current Attempt in Progress National Express reports the following costs and expenses in June 2020 for its delivery service. Indirect materials $6,400 Drivers' salaries $16,000 Depreciation on delivery equipment 11,200 Advertising 4,600 Dispatcher's salary 5,000 Delivery equipment repairs 300 Property taxes on office building 870 Office supplies 650 CEO's salary 12,000 Office utilities 990 Gas and oil for delivery trucks 2,200 Repairs on office equipment 180 Determine the total amount of (a) delivery service (product) costs and (b) period costs. Delivery service (product) costs Period costs $ $