the answer is -$97 for sure.
* n, n* p+ l F) j1 _5 R; rThink about it this way
4 \- G @; d, \* Y' c* k5.39.217.77:88981) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)TVBNOW 含有熱門話題,最新最快電視,軟體,遊戲,電影,動漫及日常生活及興趣交流等資訊。4 K! ]$ b$ P; D8 N% f( Y
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 |