原帖由 prozzy 於 2007-5-18 23:05 發表。 . s- t |$ T, @; C. k h" H; }2 h) V9 j- z
the answer is -$97 for sure.
4 \, y1 d1 c0 \Think about it this way 5.39.217.77! N7 W8 E$ @; t1 s6 g
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)公仔箱論壇$ U; W$ a: ~4 \$ o" R+ }1 k
2) Now, the owner discovered that the 100 bucks is fake. You can th ... ; c. f7 C# z( T# |; Z, @
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1) very good, it the 100 bucks is real, your answer is correct, but it is fake, so your answer is wrong5.39.217.77# \# l+ J+ S' ]$ j/ H5 R
公仔箱論壇, C+ R/ c8 X8 H3 c% R0 n
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.& `" `- X9 k4 O" {1 H3 I! a% b' a* r
tvb now,tvbnow,bttvb' x2 q0 j, {, L6 W* u l
I know the answer becoz it really happening to my friend in his store in real LIFE, it can not be wrong. |