Lets break this down step by step.
4+4+4+4=16 lawns a week.
16+16+16+16=64 lawns a month.
64+64+64+64=256 lawns a year.
Then we take 256 x $25 to get $6,400 last year.
6,400<---Answer
-Seth
Let c represent the original amount that this guy had saved up.
He spent 25% of this amount, or 0.25c, on the printer.
To progress further, we have to know how much the printer cost.
Supposing that the printer cost $100 (which we do not know as a fact), this would be equal to 0.25c.
Thus, his savings originally amounted to c = $100/0.25 = $400.