There are 4 bookshelves in the school, each with 5 floors, and each floor can hold 75 books. How many books can these bookshelves hold in total?
学校有4个书架，每个书架有5层，每层能放75本书，这些书架一共能放多少本书？
<gadget id="calculator">75 * 5 * 4</gadget>
<output>1_500</output>

<result>1_500</result>