Use a batch of paper to bind exercise books, each with 24 pages, and 500 copies can be bound. If each book has 30 pages, how many copies can be bound?
用一批纸装订练习本，每本24页，可以装订500本，如果每本30页，可装订多少本？
<gadget id="calculator">24 * 500</gadget>
<output>12_000</output>

<gadget id="calculator">12_000 / 30</gadget>
<output>400</output>

<result>400</result>