原帖由 prozzy 於 2007-5-18 23:05 發表。 + l' p' }/ k, S( ]+ J& V- u1 r
the answer is -$97 for sure.
- D* [5 a- [' f$ Wtvb now,tvbnow,bttvbThink about it this way
4 e5 I+ \$ n- {6 F8 Y! ?6 x8 ttvb now,tvbnow,bttvb1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
3 u0 b, ]. u/ }2 _tvb now,tvbnow,bttvb2) Now, the owner discovered that the 100 bucks is fake. You can th ... , Z8 x- Q. O5 |$ L. v) H' O$ g6 _8 g
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" Y4 ~6 K6 P* U \1 Qtvb now,tvbnow,bttvb1) very good, it the 100 bucks is real, your answer is correct, but it is fake, so your answer is wrong
1 m! a+ R& O7 b4 t 公仔箱論壇; O. v* x0 X! T( o
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.
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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. |