Students in the third and fourth grades of our school donated 360 books to the library, and put them into 4 bookshelves. Each shelf has 3 floors. How many books are placed on each floor on average?
我校三、四年级学生共向图书室捐书360本，分别放入了4个书架，每个书架有3层，平均每层放了多少本？
<gadget id="calculator">360 / 4 / 3</gadget>
<output>30</output>

<result>30</result>