the answer is -$97 for sure. ( ]% r% {# @1 Z0 [
Think about it this way 公仔箱論壇+ S- X5 s& v- N' J
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)$ C, v# G4 L6 e( o1 g! F0 r
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 |