Two trains are running towards each other from A and B. It takes 4 hours for the slow train to travel from A to B, which is 1/3 more time than the express train for traveling from B to A. If the two trains leave at the same time, the fast train will take more time than the slow train when they meet. Travel 80 kilometers, find the distance between A and B.
两列火车从甲、乙两地相向而行，慢车从甲到乙要4小时，比快车从乙到甲多用(1/3)时间，如果两车同时开出，那么相遇时快车比慢车多行80千米，求甲、乙两地的距离．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 + (1/3)</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">4 / (4/3)</gadget>
<output>3</output>

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

<gadget id="calculator">(1/3) + (1/4)</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">1 / (7/12)</gadget>
<output>12/7 = around 1.714286</output>

<gadget id="calculator">(1/3) * (12/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">1 - (4/7)</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(4/7) - (3/7)</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">80 / (1/7)</gadget>
<output>560</output>

<result>560</result>