the answer is -$97 for sure.
/ s$ J/ D q! R) M+ S3 `Think about it this way
& i5 Y5 r3 \% v8 q/ g9 t- ?% c1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
8 v; t, }/ h2 e; O- c" U& L公仔箱論壇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
| 
發表於 2007-5-19 03:21 PM
| 
發表於 2007-5-21 03:49 AM
| 