Car A and car B leave from places A and B at the same time. When car A travels the entire distance (3/7), car B travels 42 kilometers. When car A arrives at point B, car B leaves. The whole process (7/10). How many kilometers are there between A and B?
甲、乙两车分别从A、B两地同时相对开出，当甲车行了全程的(3/7)时，乙车行了42千米，当甲车到达B地时乙车行了全程的(7/10)．A、B两地相距多少千米？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

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

<gadget id="calculator">1 / (3/7)</gadget>
<output>7/3 = around 2.333333</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(7/3) / (7/10)</gadget>
<output>10/3 = around 3.333333</output>

<gadget id="calculator">42 * (10/3)</gadget>
<output>140</output>

<result>140</result>