the answer is -$97 for sure. 3 P$ J. A* L! U
Think about it this way
0 { E4 e5 v6 n1 T4 S& v- i1 E1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)www3.tvboxnow.com( @% B/ H9 V* c! l# a1 |2 J9 Z
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 |