the answer is -$97 for sure. e3 t& R6 k4 a" [0 o; j* d) e) a
Think about it this way 5.39.217.77) q5 Q$ ? p$ C7 W* U _! z8 E8 ~, r
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
$ W5 b6 T- Y# x1 j6 G& R2) 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 |