There is a batch of books in the school library, and after lending out 40%, 360 new books are bought. At this time, the number of books is 3/4 of the original stock. How many books did the school library have?
学校图书馆存有一批书，借出40%以后，又买进新书360本，这时的书是原来存书量的(3/4)，学校图书馆原来有书多少本？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</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">(3/4) - (3/5)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">360 / (3/20)</gadget>
<output>2_400</output>

<result>2_400</result>