Answer
(a) Interest on notes payable of 300 USD is accrued.
(b) Service revenue earned but unmilled total 1,400 USD
(c) Salaries of 780 USD
Work Step by Step
(a) Interest expenses 300 USD; interested payable 300 USD
(b) Accounts receivable 1,400 USD; service revenue 1,400 USD
(c) Salaries expenses 780 USD; salaries payable 780 USD