A book, Xiao Ming read (2/5), just read 40 pages, how many pages in this book?
一本书，小明看了(2/5)，刚好看了40页，这本书一共多少页？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">40 / (2/5)</gadget>
<output>100</output>

<result>100</result>