The ratio of pages read to pages not read in a book is 5:3, and 25 pages have been read. How many pages are there in this book?
一本书看了的和未看的页数的比是5：3，已经看了的是25页，这本书一共多少页．
<gadget id="calculator">25 / 5</gadget>
<output>5</output>

<gadget id="calculator">3 + 5</gadget>
<output>8</output>

<gadget id="calculator">5 * 8</gadget>
<output>40</output>

<result>40</result>