A simple 3rd grade math problem

[Amnorix]

Originally Posted by Msmith

Fax has a garage sale. The cost of the sweater is $18. Fax sells it for $21. A person buys the sweater and gives Fax a $100 bill. Fax goes to his neighbor for change. He gives the buyer $79 back. The next day the neighbor tells Fax that the $100 is faked. Fax gives the neighbor back $100. How much money does Fax lose?

$200, or $197, or "can't quite determine", depending on how you read this.

$100 to the neighbor who he had to give a real $100 in replacement of the fake.

$79 in real money paid to the jerk who passed off the phony bill.

And $18 or $21, the value of the sweater that he's lost without getting a (legitimate) dime for it.

The confusion is that the OP says the "cost" of the sweater is $18 but someone pays $21 for it. The real number depends on what the real value of the sweater is to a legimate buyer paying in real cash. If the real value of teh sweater is $18, then the answer if $197. If $21, then $200. If something else, then $100+$79+[something else]