the answer is -$97 for sure. 5.39.217.77:8898 [% v8 t; c6 y# `. Q4 r6 X
Think about it this way 公仔箱論壇1 l$ J8 Y, |) A9 _! x! r
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
/ ~; z& s; k7 l5 _# ~$ Atvb now,tvbnow,bttvb2) 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 |