the answer is -$97 for sure. # ]+ A2 A1 C8 J9 ]
Think about it this way 4 d6 f2 R/ p3 c+ s
1) 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。* i: z% [1 U& b: C8 Z% g4 m
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 |