Answer:
a. Cash basis - Service revenue is $900
b. Accrual basis - Service revenue is $2,100 (which is $1200 + $900)
Step-by-step explanation:
In accounting, there are 2 basis for recognizing transactions; these are cash basis and accrual basis.
In cash basis, sales and expenses are not recorded unless cash has been collected and paid respectively. In the accrual basis of accounting, expenses and sales are recorded when incurred and earned respectively.
Revenue earned under the accrual basis would therefore include the revenue for which cash has been collected and those for which cash is yet to be collected.