The printing factory binds exercise books with a batch of paper. If each book has 20 pages, 300 copies can be bound. If 250 exercise books are to be bound, how many pages should each be bound? (proportional solution)
印刷厂用一批纸装订练习本，如果每本装20页，可以装订300本．如果要装订250本练习本，每本应装订多少页？(比例解)
<gadget id="calculator">20 * 300</gadget>
<output>6_000</output>

<gadget id="calculator">6_000 / 250</gadget>
<output>24</output>

<result>24</result>