the answer is -$97 for sure. $ b$ }9 e# e) y0 x
Think about it this way ' [5 k- p8 {* v- l, `8 m- p+ B
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
! I) L1 X* s: v9 H& e" x7 \9 }0 Ctvb 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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