The school bought some books, including 300 story books and 180 science and technology books. The two kinds of books accounted for 60% of the total number of these books. How many books did the school buy in total?
学校买来一些图书，其中故事书300本，科技书180本，两种书的数量共占这些图书总数的60%，学校一共买来图书多少本？
<gadget id="calculator">300 + 180</gadget>
<output>480</output>

<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">480 / (3/5)</gadget>
<output>800</output>

<result>800</result>