Read a book with a smile, the ratio of the number of pages you have read to the number of pages you have not read is 1:4, if you read another 10 pages, the number of pages you have read accounts for 1/4 of the total number of pages in the book. how many pages
笑笑看一本书，已看的页数与未看的页数的比是1：4，如果再看10页这时已看页数占全书总页数的1/4，这本书共有多少页？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + 4</gadget>
<output>5</output>

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

<gadget id="calculator">(1/4) - (1/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">10 / (1/20)</gadget>
<output>200</output>

<result>200</result>