Xinhua Bookstore shipped a batch of books, sold 420 copies, and left (5/12). How many books are there in total?
新华书店运来一批图书，卖出420本，还剩(5/12)．这批图书共有多少本？
<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">1 - (5/12)</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">420 / (7/12)</gadget>
<output>720</output>

<result>720</result>