the answer is -$97 for sure. os.tvboxnow.com" S# P* @' t8 _* A
Think about it this way
4 @* T- n2 \$ v: K$ y公仔箱論壇1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)/ _" Z7 `2 k2 P/ r
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 |