Two cars, A and B, start from A and B at the same time and go towards each other. After 6 hours, the two cars meet. It is known that the whole journey of B (1/21) per hour, A travels 60 kilometers per hour, A and B How many kilometers are the two places?
甲乙两车分别从A、B两地同时出发相向而行，两车经过6小时相遇，已知乙车每小时行全程的(1/21)，甲车每小时行60千米，A、B两地多少千米？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 21</gadget>
<output>1/21 = around 0.047619</output>

<gadget id="calculator">(1/6) - (1/21)</gadget>
<output>5/42 = around 0.119048</output>

<gadget id="calculator">60 / (5/42)</gadget>
<output>504</output>

<result>504</result>