Answer:
=810+2430 => $3240.
Step-by-step explanation:
For the year 2021, the employee will only have to pay the remaining 3-month interest i.e, October, November and December (36000 * 9% * (3/12)), which becomes 810.
For the year 2022, the employee has to pay the remaining 9-month interest (36000 * 9% * (9/12)), which becomes 2430.
So the total interest revenue becomes = 810+2430 = 3240.
Hope this helps.
Goodluck.