Xiao Ming reads a storybook. He reads 30% of the whole book on the first day and 25% of the whole book on the second day. He reads 15 more pages on the first day than on the second day. How many pages does this storybook have?
小明看一本故事书，第一天看了全书的30%，第二天看了全书的25%，第一天比第二天多看了15页，这本故事书共有多少页？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

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

<gadget id="calculator">(3/10) - (1/4)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">15 / (1/20)</gadget>
<output>300</output>

<result>300</result>