Use a batch of paper to bind the exercise book. If each book is bound with 60 pages, then 30 books can be bound. If you want to bind 20 more books, how many pages should be bound in each book?
用一批纸装订练习本．若每本装订60页，则可以装订30本．如果要多装订20本，那么每本应该装订多少页？
<gadget id="calculator">60 * 30</gadget>
<output>1_800</output>

<gadget id="calculator">30 + 20</gadget>
<output>50</output>

<gadget id="calculator">1_800 / 50</gadget>
<output>36</output>

<result>36</result>