There is a 300-meter circular runway. Two students, A and B, start from the same place in the same direction. A walks at a speed of 55 meters per minute, and B runs at a speed of 155 meters per minute. How many minutes does it take for B to catch up with A for the second time?
有一个300米的环形跑道．甲、乙两个同学从同一地点同向出发，甲以每分钟55米的速度步行，乙以每分钟155米的速度跑步，乙在第二次追上甲时用了多少分钟？
<gadget id="calculator">155 - 55</gadget>
<output>100</output>

<gadget id="calculator">2 / 100</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">300 * (1/50)</gadget>
<output>6</output>

<result>6</result>