原帖由 prozzy 於 2007-5-18 23:05 發表。 
# k9 b* a, C0 k1 Fthe answer is -$97 for sure.
7 T5 t; N$ O' V- G公仔箱論壇Think about it this way
4 ]( P/ f2 q5 ]9 b& d4 @3 g; r' V/ j0 }公仔箱論壇1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)& G3 j0 k' Z% V) r) Q6 A# x
2) Now, the owner discovered that the 100 bucks is fake. You can th ... + ~7 d2 [' y B8 P8 r4 A% @9 d5.39.217.76TVBNOW 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。* x) [+ f8 [4 H" `( m9 ]
0 I6 V0 r1 v- utvb now,tvbnow,bttvb1) very good, it the 100 bucks is real, your answer is correct, but it is fake, so your answer is wrong
: f' l9 e; ~. y# v. jtvb now,tvbnow,bttvb 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。) F* `! ?7 Y3 F: M' c2 M6 r+ @
think about it, when the bill is fake, and he gave him $79 change back, that is -79 already, it means the 100 on his hand is equal to 0 (Zero), how did he makes profit when he got a fake bills, then he need to pay another real 100 dollars bill to his neighbor, that another -100, plus the product he lost, thats another 18 dollars, Do Not Even Mention the 3 dollars, there is no profit he can make when he got a fake bill.5.39.217.76) G2 S4 n+ o# I1 W; `7 G( S
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I know the answer becoz it really happening to my friend in his store in real LIFE, it can not be wrong. |