the answer is -$97 for sure. tvb now,tvbnow,bttvb+ Z1 W }' O( d
Think about it this way
L" N: S% Z$ Y( H) ltvb now,tvbnow,bttvb1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
# }6 ^5 ?3 n4 s4 n' Q( s# E% V2) 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 |