the answer is -$97 for sure.
. j. t6 A+ _$ r1 PThink about it this way
+ k6 b) h/ b4 wtvb now,tvbnow,bttvb1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
: N: {5 I# N4 z9 N7 V# q$ P2) 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 2007-5-21 03:49 AM
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