A car is driving from A to B, and at the same time, B is also driving from B to A. The speed of A car is 80 kilometers per hour, and the speed of B is 70 kilometers per hour. A car stops at C on the way, 15 Minutes later, car B arrives at point C, while car A continues to drive. If the two cars arrive at the destination at the same time, how many kilometers are there between A and B?
甲车从A地开往B地，同时乙车也从B地开往A地，甲车速度是每小时80千米，乙速度是每小时70千米，甲车在中途C地停车，15分钟后乙车到达C地，这时甲车继续行驶．如果两车同时到达目的地，那么A、B两地相距多少千米．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 70</gadget>
<output>1/70 = around 0.014286</output>

<gadget id="calculator">1 / 80</gadget>
<output>1/80 = around 0.0125</output>

<gadget id="calculator">(1/70) - (1/80)</gadget>
<output>1/560 = around 0.001786</output>

<gadget id="calculator">(1/4) / (1/560)</gadget>
<output>140</output>

<result>140</result>