原帖由 prozzy 於 2007-5-18 23:05 發表。 
/ n! {0 @! i9 V4 G4 ~6 cthe answer is -$97 for sure.
( V! X% R6 |) _% N( X4 C8 ^, u5.39.217.76Think about it this way
X& {9 i) ?2 |公仔箱論壇1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)5.39.217.760 H5 Y6 P9 q- j5 B3 S# }7 x
2) Now, the owner discovered that the 100 bucks is fake. You can th ... tvb now,tvbnow,bttvb7 T+ i' }& @' ]- T. t
2 X' P4 O. {/ M. I( Z0 ?TVBNOW 含有熱門話題,最新最快電視,軟體,遊戲,電影,動漫及日常生活及興趣交流等資訊。 TVBNOW 含有熱門話題,最新最快電視,軟體,遊戲,電影,動漫及日常生活及興趣交流等資訊。8 W- }7 A4 ~5 p1 J" i
1) very good, it the 100 bucks is real, your answer is correct, but it is fake, so your answer is wrong
u$ A8 b; Z: Z( F5 ^! g" j- V公仔箱論壇
, E, ?4 | u- O8 LTVBNOW 含有熱門話題,最新最快電視,軟體,遊戲,電影,動漫及日常生活及興趣交流等資訊。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.
. |# i& b! _' Y) E5.39.217.76 TVBNOW 含有熱門話題,最新最快電視,軟體,遊戲,電影,動漫及日常生活及興趣交流等資訊。- \- f. z7 t; b( o
I know the answer becoz it really happening to my friend in his store in real LIFE, it can not be wrong. |