Xiaohong reads a story book. On the first day, she reads half of the book and 10 pages. On the second day, she reads the remaining half and 10 pages. On the third day, she reads 10 pages and finishes it. How many pages does this story book have?
小红看一本故事书，第一天看了这本书的一半又10页，第二天看了余下的一半又10页，第三天看了10页正好看完．这本故事书共有多少页．
<gadget id="calculator">10 + 10</gadget>
<output>20</output>

<gadget id="calculator">20 * 2</gadget>
<output>40</output>

<gadget id="calculator">40 + 10</gadget>
<output>50</output>

<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<result>100</result>