A circular runway is 400 meters long. A runs 160 meters per minute, and B runs 120 meters per minute. They start from the same place and the same direction at the same time. How many minutes will it take for A to catch up with B for the first time?
一条环形跑道长400米，甲每分钟跑160米，乙每分钟跑120米，两人同时由同一地点同方向起跑，那么甲要经过几分钟才能第1次追上乙？
<gadget id="calculator">160 - 120</gadget>
<output>40</output>

<gadget id="calculator">400 / 40</gadget>
<output>10</output>

<result>10</result>