the answer is -$97 for sure. 公仔箱論壇: p( O; \, s# ^& `
Think about it this way 公仔箱論壇5 }/ G% ^ ]1 N
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
6 |. J2 S) m# e0 t$ {/ Y/ wtvb 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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