原帖由 prozzy 於 2007-5-18 23:05 發表。 
4 } A& w) n5 c* {* ^- [8 h6 Q. ^the answer is -$97 for sure.
! T- v: \/ j1 MThink about it this way
9 P4 G, y# M# _6 W1 Y1 ]' g' rtvb now,tvbnow,bttvb1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
) l0 N' x% ~1 _$ ]: N0 c4 u! J% V1 _tvb now,tvbnow,bttvb2) Now, the owner discovered that the 100 bucks is fake. You can th ... 2 D% Q _- w: V) s. w9 _+ y5.39.217.76
) ~* w9 }7 V$ z* }- @tvb now,tvbnow,bttvb # Y5 d' B% h7 W. `
1) very good, it the 100 bucks is real, your answer is correct, but it is fake, so your answer is wrong" _, p6 H, z; x
5 Q9 b! N. @( J- v5.39.217.76think 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2 F8 o! f4 Z- k) f
% F9 Y8 L3 _: RI know the answer becoz it really happening to my friend in his store in real LIFE, it can not be wrong. |