Use a batch of paper to bind exercise books, if each book is bound with 25 pages, 36 books can be bound; if each book is bound with 15 pages, how many books can be bound? (Solve with ratio)
用一批纸装订练习本，如果每本装订25页，可以装订36本；如果每本装订15页，可以装订多少本？(用比例解)
<gadget id="calculator">25 * 36</gadget>
<output>900</output>

<gadget id="calculator">900 / 15</gadget>
<output>60</output>

<result>60</result>