原帖由 prozzy 於 2007-5-18 23:05 發表。 
# Q+ N; n! m. D" y: htvb now,tvbnow,bttvbthe answer is -$97 for sure. 5.39.217.765 Z& [: W- \ u+ s8 u$ |9 l/ U
Think about it this way
( N0 o8 ^) B4 \! A# O. P/ U( ]3 F公仔箱論壇1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
- [9 } l7 s7 H1 O. Ptvb now,tvbnow,bttvb2) Now, the owner discovered that the 100 bucks is fake. You can th ... $ I9 s7 E$ r- K4 D# D5.39.217.760 v& ]0 I/ t% H: ]8 D7 z
4 e8 j+ N, Q& K1 m5 R1) very good, it the 100 bucks is real, your answer is correct, but it is fake, so your answer is wrong
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+ G+ h2 q0 l0 p( i5.39.217.76think 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.公仔箱論壇1 R! V4 h1 G4 Q# P
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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. |