the answer is -$97 for sure. 5.39.217.773 J; S$ i1 r/ p
Think about it this way 5.39.217.77% I b0 `- n/ b- w F# o6 c0 Z
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
3 ~+ ~7 Y, i) U9 n5 B3 L9 g2 a! H5 ~公仔箱論壇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 |