The students in the fifth grade helped the library sort out the books. In the first week, they sorted out 40% of the books. After sorting out 120 books in the second week, there were still 60 books left to be sorted out. How many books are there in the library?
五年级的同学帮图书馆整理书籍，第一周整理了全部的40%，第二周整理了120本后还剩60本没有整理，图书馆一共有多少本书？
<gadget id="calculator">120 + 60</gadget>
<output>180</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">180 / (3/5)</gadget>
<output>300</output>

<result>300</result>