Two trains, A and B, depart from cities A and B at the same time and meet at 4 o'clock. When they meet, the ratio of the distance traveled by the two cars is 3:4. It is known that the second car travels 60 kilometers per hour. Find the distance between A and B in kilometers?
甲、乙两列火车同时从A、B两城相向开出，4时相遇．相遇时，两车所行路程的比是3：4，已知乙车每时行60千米．求A、B两地相距多少千米？
<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">4 / (4/7)</gadget>
<output>7</output>

<gadget id="calculator">60 * 7</gadget>
<output>420</output>

<result>420</result>