Science and technology books in the school library account for 25% of the total number of books, and story books account for 15% of the total number of books. There are 12,800 science and story books in total. How many books are there in the school?
学校图书馆科技书占图书总数的25%，故事书占图书总数的15%，科技书和故事书一共有12800本，学校共有图书多少本？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(1/4) + (3/20)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">12_800 / (2/5)</gadget>
<output>32_000</output>

<result>32_000</result>