Xiaohong and Xiaoming start at the same place on a circular runway with a diameter of 40m, and walk opposite each other. Xiaohong walks 30.8 meters per minute, and Xiaoming walks 32 meters per minute. After a few minutes, the two meet for the first time?
小红和小明在一个直径40m的圆形跑道的同一处出发，相背而行，小红每分钟走30.8米，小明每分钟走32米，两人几分钟后第一次相遇？
<gadget id="calculator">30.8 + 32</gadget>
<output>62.8</output>

<gadget id="calculator">40 / 62.8</gadget>
<output>0.636943</output>

<gadget id="calculator">3.14 * 0.636943</gadget>
<output>2.000001</output>

<result>2.000001</result>