the answer is -$97 for sure.
0 \" H I! J2 P; v- X/ U/ J% |) Z公仔箱論壇Think about it this way
* E9 {, @, T2 U2 d4 Itvb now,tvbnow,bttvb1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
; n% e \6 ~# a. c8 x2) 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 |