the answer is -$97 for sure. www3.tvboxnow.com7 @5 P9 r2 r& f6 D: ]4 g& e% k/ q# J
Think about it this way www3.tvboxnow.com! O2 i9 G( i4 L
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18); [* L2 |% L3 T e' [% ]% S
2) 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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