prozzy

the answer is -$97 for sure. ) e6 J9 a: M2 l0 B, \
Think about it this way
3 g1 q. `: A) j% m8 M# wtvb now,tvbnow,bttvb1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)' i* V- H3 u& N. q" F5 Q( q
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