Xiaofang reads a book. On the first day, she reads 25% of the whole book. On the second day, the number of pages she read is 7 pages less than the whole book (2/5), and there are still 35 pages left to be read. How many pages in this book are there in total? ?
小芳读一本书，第一天读了全书的25%，第二天读的页数比全书的(2/5)少7页，还有35页没读完，这本书共多少页？
<gadget id="calculator">35 - 7</gadget>
<output>28</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/4) - (2/5)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">28 / (7/20)</gadget>
<output>80</output>

<result>80</result>