Originally posted by: mooncancook
hmm let me think again.
He gains $3 total from the sale (21-18). Then he lose $100 to the neighbor for the fake bill. 100-3=97.
So my final answer is $97.
Exactly where does he gain this $3? If the product never sold, sure. But, if I had walked in next and bought it (or if the guy had used a legit $100), he would have made that $3.
