The ratio of comic books to literary books in the library is 2:5, there are 90 literary books, how many comic books are there.
图书室里连环画和文艺书的比是2：5，文艺书有90本，连环画有多少本．
<gadget id="calculator">90 / 5</gadget>
<output>18</output>

<gadget id="calculator">18 * 2</gadget>
<output>36</output>

<result>36</result>