Xiao Ming reads a story book. He reads 25% of the whole book on the first day, and (1/5) of the whole book on the second day. He reads a total of 225 pages in two days. How many pages does this book have?
小明看一本故事书，第一天看了全书的25%，第二天看了全书的(1/5)，两天共看225页，这本书有多少页？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/5) + (1/4)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">225 / (9/20)</gadget>
<output>500</output>

<result>500</result>