There are 3 bookshelves in the library, each shelf has 5 floors, and each floor contains 40 books. How many books are there in the library?
图书馆里有3个书架，每个书架有5层，每层有40本书，图书馆里一共有多少本书？
<gadget id="calculator">40 * 5 * 3</gadget>
<output>600</output>

<result>600</result>