Use a batch of exercise books of the same size to bind. If each book has 30 pages, 120 books can be bound. Now use this batch of paper to bind 100 books. How many pages should be bound in each book? (answer with ratio)
用一批装订同样大小的练习本，如果每本30页，可装订120本，现用这批纸装订100本，每本应装订多少页？(用比例解答)
<gadget id="calculator">120 * 30</gadget>
<output>3_600</output>

<gadget id="calculator">3_600 / 100</gadget>
<output>36</output>

<result>36</result>