Wang Ming reads a storybook. He reads the whole book (1/4) on the first day and the whole book (7/20) on the second day. He reads 15 more pages on the second day than on the first day. How many pages are there?
汪明看一本故事书，第一天看了全书的(1/4)，第二天看了全书的(7/20)，第二天比第一天多看15页，这本故事书有多少页？
<gadget id="calculator">7 / 20</gadget>
<output>7/20 = around 0.35</output>

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

<gadget id="calculator">(7/20) - (1/4)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">15 / (1/10)</gadget>
<output>150</output>

<result>150</result>