I read 20% of a storybook on the first day, and the remaining 31.25% on the second day. At this time, there are 55 pages left. How many pages are there in this book?
一本故事书第一天看了20%，第二天看了余下的31.25%，这时还剩下55页没有看，这本书共有多少页？
<gadget id="calculator">31.25 / 100</gadget>
<output>0.3125</output>

<gadget id="calculator">1 - 0.3125</gadget>
<output>0.6875</output>

<gadget id="calculator">55 / 0.6875</gadget>
<output>80</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">80 / (4/5)</gadget>
<output>100</output>

<result>100</result>