The lengths of two trains are 280 meters and 200 meters respectively, and the speeds are 5 meters per second and 3 meters per second respectively. If A chases after B, the time for the two vehicles to meet is 60 seconds. If two cars start from two places and drive towards each other, how many seconds will it take to meet each other?
两列火车长度分别为280米、200米，速度分别为5米/秒、3米/秒．如果甲在后面追乙，两车交会的时间为60秒．如果两车从两地分别出发，相向而行，交会的时间为多少秒．
<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">2 * 60</gadget>
<output>120</output>

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

<gadget id="calculator">120 / 8</gadget>
<output>15</output>

<result>15</result>