Xiao Min reads a book, read 6 pages on the first day, then read 4 more pages every day than the previous day, and read the whole book (2/5) on the third day, continue to read like this, and finish reading on the number of days.
小敏读一本书，第一天读6页，以后每天比前一天多读4页，读到第三天读了全书的(2/5)，这样继续读下去，第多少天读完．
<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<result>6</result>