the answer is -$97 for sure. 公仔箱論壇5 N$ M! W8 b. n' z
Think about it this way " g+ y: }. v: A+ b) u
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
4 K a6 [* D: N, R- j# STVBNOW 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。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 |