Xiaochen started to read a book from the first day of school, read the whole book (1/20) on the first day, read 6 pages more than the first day (3/5) on the second day, and read 18 pages, so how many pages does this book have?
晓晨从开学第一天开始看一本书，第一天看了全书的(1/20)，第二天看的比第一天的(3/5)多6页，第二天看了18页，那么这本书共有多少页？
<gadget id="calculator">18 - 6</gadget>
<output>12</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">12 / (3/5) / (1/20)</gadget>
<output>400</output>

<result>400</result>