Hu Jun set off from his home to the county seat by motorcycle at a speed of 720 m/min and arrived in 25 minutes; after finishing his business, he returned by the same road and arrived home in 30 minutes. What was the speed in meters per minute when he returned?
胡军骑摩托车从家出发去县城，行驶的速度是720米/分，25分钟到达；办完事后按原路返回，用了30分钟到家．他返回时行驶的速度是多少米/分钟？
<gadget id="calculator">25 / 30</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">720 * (5/6)</gadget>
<output>600</output>

<result>600</result>