Sakura and Xiaoting are running on a 200-meter-long circular track. They start from the same place at the same time in a counterclockwise direction. Sakura runs 6 meters per second, and Xiaoting runs 4 meters per second. How long will it take for Sakura to catch up? Xiaoting?
小樱和小婷在200米长的环形跑道上跑步，她们从同一地点沿逆时针方向同时出发，小樱每秒跑6米，小婷每秒跑4米，多长时间后小樱追上小婷？
<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<gadget id="calculator">200 / 2</gadget>
<output>100</output>

<result>100</result>