The school bought 3 new bookshelves, and each bookshelf has 4 floors. In this way, a total of 480 books can be placed on the bookshelves. How many books are placed on each floor on average?
学校新买了3个书架，每个书架有4层，这样书架上一共可放书480本，平均每层放书多少本？
<gadget id="calculator">480 / 4 / 3</gadget>
<output>40</output>

<result>40</result>