A and B are running along a 400-meter circular track. They start from the same place at the same time and walk in the same direction. A's speed is 290 meters per minute, and B's speed is 250 meters per minute. After how many minutes, A runs 2 laps more than B? (Solution in your favorite way)
甲、乙两人沿着400米的环形跑道跑步，他们同时从同一地点出发，同向而行．甲的速度是每分钟290米，乙的速度是每分钟250米，经过多少分钟甲比乙多跑2圈？(用你喜欢的方法解)
<gadget id="calculator">400 * 2</gadget>
<output>800</output>

<gadget id="calculator">290 - 250</gadget>
<output>40</output>

<gadget id="calculator">800 / 40</gadget>
<output>20</output>

<result>20</result>