The bookkeeper for Tran Company asks you to prepare the following accrual adjusting entries at December 31. Use these account titles: Service Revenue, Accounts Receivable, Interest Expense, Interest Payable, Salaries and Wages Expense, and Salaries and Wages Payable. 

a. Interest on notes payable of $300 is accrued. 

b. Services performed but unbilled totals $1,700. 

c. Salaries of $780 earned by employees have not been recorded.