Wang Li and Li Ming are running on a circular track. They start from the same place at the same time and walk in opposite directions. Wang Li runs 3 meters per second, and Li Ming runs 4 meters per second. After 1 minute and 40 seconds, the two meet. How long is the runway?
王丽和李明在环形跑道上跑步，两人同时从同一地点出发，反向而行．王丽每秒钟跑3米，李明每秒钟跑4米，经过1分40秒两人相遇，跑道长多少米？
<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">7 * 100</gadget>
<output>700</output>

<result>700</result>