story book, Xiaojing read 15% of the whole book on the first day and 20% of the whole book on the second day, 63 pages in total in two days. How many pages are there in this storybook?
一本故事书，晓静第一天看了全书的15%，第二天看了全书的20%，两天共看了63页．这本故事书一共多少页？
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

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

<gadget id="calculator">(3/20) + (1/5)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">63 / (7/20)</gadget>
<output>180</output>

<result>180</result>