prozzy

the answer is -$97 for sure. 公仔箱論壇- U) Y. L% V7 a$ P1 D9 k
Think about it this way 5.39.217.77:88980 J. G5 F; v- X# |, I3 k
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)) ^8 w  d/ |+ |/ K( W
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