the answer is -$97 for sure. tvb now,tvbnow,bttvb' g; S; e$ V+ O
Think about it this way
! t& B9 c2 {% C1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)公仔箱論壇, R3 S% }" e1 O; n
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 |