prozzy

the answer is -$97 for sure. ; a6 \+ N. n5 i# L& S
Think about it this way 0 C: Q* o- s( {& A5 k6 a
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)公仔箱論壇" A) q5 r5 P! X( e. {! ~, i+ u
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