Dongdong reads a book, reads 4 pages a day, reads half of the book in 12 days, and then doubles the number of pages per day, how many days did it take to finish the book?
冬冬看一本书，每天看4页，12天看了这本书的一半，以后每天看的页数增加1倍，看完这本书共花了多少天？
<gadget id="calculator">96 - 48</gadget>
<output>48</output>

<gadget id="calculator">48 / 6</gadget>
<output>8</output>

<gadget id="calculator">8 + 12</gadget>
<output>20</output>

<result>20</result>