原帖由 prozzy 於 2007-5-18 23:05 發表。 
; V. I* V0 O4 C. a5.39.217.76the answer is -$97 for sure. : l1 T2 L6 R/ X4 t
Think about it this way
. B, A W5 b" ?7 w1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)tvb now,tvbnow,bttvb6 @, ` I) ^: R! F7 m
2) Now, the owner discovered that the 100 bucks is fake. You can th ... ; r( `; y7 O. T; c N
6 k! |$ F! l5 T' T$ u 5.39.217.768 w! j) B- @, z! A2 A5 Q
1) very good, it the 100 bucks is real, your answer is correct, but it is fake, so your answer is wrong
; M8 C D/ k: B7 b' |6 \5.39.217.76 tvb now,tvbnow,bttvb, x# ]2 U9 Y# Z8 l
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.& l' g% q V: b0 X; l* G5 m( s- Q t
tvb now,tvbnow,bttvb6 v% v: c1 I I
I know the answer becoz it really happening to my friend in his store in real LIFE, it can not be wrong. |