prozzy

the answer is -$97 for sure.
% `4 i2 G7 E- P, {( D  zThink about it this way
# W/ m  e8 @' @  ]6 F8 Q7 K; ~5.39.217.771) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)TVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。$ x" G- B' C$ 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