Xiao Ming and Xiao Liang run along the playground with a circumference of 450 meters. Xiao Ming runs 200 meters per minute, and Xiao Liang runs 250 meters per minute. They start from one point at the same time and walk in the same direction. After a few minutes, Xiao Liang catches up with Xiao Ming for the first time ?
小明和小亮沿着周长450米的操场跑步，小明每分钟跑200米，小亮每分钟跑250米，他们同时从一点出发同向而行，几分钟后小亮第一次追上小明？
<gadget id="calculator">250 - 200</gadget>
<output>50</output>

<gadget id="calculator">450 / 50</gadget>
<output>9</output>

<result>9</result>