the answer is -$97 for sure. 公仔箱論壇. `! G" v* o+ z2 b9 l0 q
Think about it this way tvb now,tvbnow,bttvb a) R x4 r: D! C6 t) v4 y
1) if the 100 bucks is not a fake one, the store owner will gain $3 ($21-$18)tvboxnow.com. \$ Q& Q, {( L& n( z9 j
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 |