Xiaogang reads a book. He reads the whole book (2/15) on the first day, and reads 6 more pages on the second day than on the first day. At this time, the ratio of the number of pages read to the number of remaining pages is 3 :7, How many pages does this book have?
小刚读一本书，第一天读了全书的(2/15)，第二天比第一天多读了6页，这时已读的页数与剩下的页数的比是3：7，这本书有多少页？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">2 / 15</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">(3/10) - (2/15) - (2/15)</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">6 / (1/30)</gadget>
<output>180</output>

<result>180</result>