the answer is -$97 for sure. 公仔箱論壇9 B. C, G0 N: J. F
Think about it this way 公仔箱論壇, `' |& q) T7 |7 M
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)tvb now,tvbnow,bttvb% b4 {) U$ ~5 N* t5 h
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 |
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