If you read 1/3 of a book on the first day, if you read another 60 pages, the ratio of the number of pages you have read to the rest is 7:8. How many pages does this book have?
一本书，第一天读了全书的(1/3)，如果再读60页，那么已读的页数与剩下的比是7：8，这本书共有多少页？
<gadget id="calculator">7 + 8</gadget>
<output>15</output>

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

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(7/15) - (1/3)</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">60 / (2/15)</gadget>
<output>450</output>

<result>450</result>