In a book, the ratio of the number of pages read to the number of remaining pages is 7:8. What is the number of pages read in the total number of pages?
一本书，看了的页数与剩下的页数的比是7：8，看了的页数占总页数的多少．
<gadget id="calculator">7 + 8</gadget>
<output>15</output>

<gadget id="calculator">7 / 15</gadget>
<output>7/15 = around 0.466667</output>

<result>7/15 = around 0.466667</result>