There are 6,000 books in the school library, and there are 15 bookshelves. Each shelf has 5 floors. On average, how many books are placed on each floor?
学校图书馆有6000本书，放书架到15个上，每个书架有5层，平均每层，放多少本书？
<gadget id="calculator">15 * 5</gadget>
<output>75</output>

<gadget id="calculator">6_000 / 75</gadget>
<output>80</output>

<result>80</result>