the answer is -$97 for sure.
. Z& d; i* ~% Q3 W: a$ C9 Q) ZThink about it this way
, D! R3 x6 K8 o. q1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
6 n& \0 L; ?1 X- f, w: B2) 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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