Example 3 The circular runway of the school playground is 200 meters long. A and B start off in the same direction at the same time. A walks 110 meters per minute and B walks 100 meters per minute. After how many minutes can A catch up with B?
例3学校操场的环形跑道长200米．甲乙两人同时同地朝同一方向出发．甲每分钟行110米，乙每分钟行100米．经过多少分钟后甲可以追上乙？
<gadget id="calculator">110 - 100</gadget>
<output>10</output>

<gadget id="calculator">200 / 10</gadget>
<output>20</output>

<result>20</result>