the answer is -$97 for sure. 公仔箱論壇1 U9 q2 i# h; u' l" [( r
Think about it this way 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。: D6 C( r O8 }7 Y1 o: w4 P
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)
" u0 {# v0 s- z- [5 R L$ D$ F公仔箱論壇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 |