the answer is -$97 for sure.
/ [% e, G3 g& v& \5 MTVBNOW 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 this way 2 }- e8 V! M. i
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
: K! x k n' d* h0 h) A, B. Z5 ]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。2) Now, the owner discovered that the 100 bucks is fake. You can think this as a lost of $100. therefore the overall gain is $3-$100 = -$97 |
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發表於 2007-5-21 03:49 AM
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