the answer is -$97 for sure. ( I% y0 n7 u# S' L
Think about it this way
% \4 ~) o% u9 pTVBNOW 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。1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
' S2 l! l5 E$ |2 {+ i* Q5.39.217.772) 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 |