原帖由 prozzy 於 2007-5-18 23:05 發表。 
2 `. ?9 t4 k- M E& g5.39.217.76the answer is -$97 for sure.
" w0 c" s% ?# K2 E$ |: ~5 pThink about it this way
5 E0 v8 c/ u1 L& N1 q公仔箱論壇1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)tvb now,tvbnow,bttvb: @" A& \, o4 z" [$ K
2) Now, the owner discovered that the 100 bucks is fake. You can th ... / f l3 _6 [+ Y/ D3 ^5.39.217.76! M! p, R9 W9 c0 x- H' \5 z- [1 Y
公仔箱論壇5 b2 g2 [ V! y/ p' H
1) very good, it the 100 bucks is real, your answer is correct, but it is fake, so your answer is wrongtvb now,tvbnow,bttvb6 b4 @5 c$ Y, \
tvb now,tvbnow,bttvb. H$ G" O. M6 T! z* ]
think about it, when the bill is fake, and he gave him $79 change back, that is -79 already, it means the 100 on his hand is equal to 0 (Zero), how did he makes profit when he got a fake bills, then he need to pay another real 100 dollars bill to his neighbor, that another -100, plus the product he lost, thats another 18 dollars, Do Not Even Mention the 3 dollars, there is no profit he can make when he got a fake bill.tvb now,tvbnow,bttvb& H( c- g. R* E6 @8 F3 v
tvb now,tvbnow,bttvb4 e% Q8 K" f$ A, ~: G
I know the answer becoz it really happening to my friend in his store in real LIFE, it can not be wrong. |