问题如下：
Relevant data about a medical instrument of company TDC is listed as following, the instrument is sold at $510,000. The result of the sales of the instrument at the end of 2016 is closest to:
选项：
A.a loss of $378,182
B.a gain of $378,182
C.a gain of $240,565
解释：
B is correct. Based on the given data, we can draw the equation that:
the sales of the instrument = Sale proceeds – Carrying amount
= Sale proceeds – (Acquisition cost – Accumulated depreciation)
= 510,000 – {200,000 – [((200,000 –50,000)/11 years) × 5 years]}
= 378,182.
折旧为什么要扣掉50000剩余价值，花了20万，应该用20万直接折旧吧？
