It takes 6 hours for the express train to go from place A to place B, and for the slow train to travel 60 kilometers per hour from place B to place A. The two cars leave opposite places at the same time and meet each other in 4 hours. What is the distance in kilometers between places A and B? ?
快车从甲地开往乙地要6小时，慢车从乙地开往甲地每小时行60千米，两车同时从两地相对开出，4小时相遇，甲乙两地的路程是多少千米？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/6) * 4</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">4 / (1/3)</gadget>
<output>12</output>

<gadget id="calculator">60 * 12</gadget>
<output>720</output>

<result>720</result>