the answer is -$97 for sure. % [5 g" @* L5 h& m }7 z" o
Think about it this way ( m! p/ B3 x$ |
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
; ?0 Y: O, ^2 M' R5 p; s4 Z1 Ktvb now,tvbnow,bttvb2) 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 |
發表於 2007-5-16 03:12 AM
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發表於 2007-5-19 03:21 PM
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發表於 2007-5-21 03:49 AM
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