the answer is -$97 for sure. 公仔箱論壇+ P# C3 S! \* y& g1 s x- z' I7 [
Think about it this way 公仔箱論壇4 k% h' t& u: ?0 }2 P% E9 \" a
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
! p# j! y3 H5 H0 s3 @9 Ntvb now,tvbnow,bttvb2) 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
| 