the answer is -$97 for sure.
) K/ A# w0 ?5 P" \& W8 |6 F- ^os.tvboxnow.comThink about it this way
/ ~: a( E7 c" R; _) ?% r- C/ a& UTVBNOW 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-$18)$ ?$ b7 A w4 O9 C. g' X$ A
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 |