the answer is -$97 for sure.
( u6 J3 W' }1 O' k" Y* K2 B2 P$ R5.39.217.76Think about it this way
0 ?3 S) v( }0 J( M. r# ~tvb now,tvbnow,bttvb1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18). M: c! S/ m) i$ k5 U
2) Now, the owner discovered that the 100 bucks is fake. You can think this as a lost of $100. therefore the overall gain is $3-$100 = -$97 |