the answer is -$97 for sure. 公仔箱論壇4 C- l; O- @7 e! }
Think about it this way 7 @9 p* P Q, K
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。) R0 Y% \% P% b* i2 A5 A
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 |