Xiaoqian read a book called "Children's Literature". I read it on the first day (1/5), and read page 25 on the second day. At this time, I happened to read this book (9/20). How many pages does this "Children's Literature" have?
小骞同学看一本《儿童文学》，第一天看了它的(1/5)，第二天看了25页，这时正好看了这本书的(9/20)．这本《儿童文学》有多少页？
<gadget id="calculator">9 / 20</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(9/20) - (1/5)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">25 / (1/4)</gadget>
<output>100</output>

<result>100</result>