the answer is -$97 for sure. TVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。: [# ^2 Y4 E+ j( h8 O5 W: H9 R
Think about it this way 0 [- F( t# g# N4 C* n, [
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)tvb now,tvbnow,bttvb, B3 |& ~6 b% @9 }. T
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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