I don't understand how you got that answer. The one you claim is right.
Judging by the data you gave.
you're basically saying...
He'd get 30k for 30 years.
for 5 years he gets 800 per year.
so it would be 900,000 + 4000 = 904,000.
That is if you start from 2010
You didn't mention a date you start from.
I think this question is Missing something. Or maybe I'm miss understanding something.