Two trains, A and B, depart from cities A and B in opposite directions at the same time, and meet each other in 5 hours. When they meet, the ratio of the distance traveled by A and B is 3:5, and it is known that B travels 80 kilometers per hour. What is the distance in kilometers between cities A and B?
甲、乙两列火车同时从A、B两城相向开出，5小时相遇．相遇时，甲、乙两车所行的路程的比是3：5，已知乙车每时行80千米．求A、B两城相距多少千米？
<gadget id="calculator">80 * 5</gadget>
<output>400</output>

<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">400 / (5/8)</gadget>
<output>640</output>

<result>640</result>