When Xiao Ming reads a book, he reads 15% of the book on the first day, and 25 pages on the second day, leaving 60% of the book unread. How many pages does this book have?
小明看一本图书，第一天看了全书的15%，第二天看了25页，还剩下全书的60%没看，这本书有多少页？
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/20) - (3/5)</gadget>
<output>1/4 = around 0.25</output>

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

<result>100</result>