Students have to sort out 200 books, and sort out 40 books in 20 minutes. According to this progress, how many minutes will it take to finish sorting?
同学们要整理200本图书，20分钟整理出40本，照这样的进度，还要多少分钟才能整理完？
<gadget id="calculator">200 - 40</gadget>
<output>160</output>

<gadget id="calculator">40 / 20</gadget>
<output>2</output>

<gadget id="calculator">160 / 2</gadget>
<output>80</output>

<result>80</result>