Xiao Cong and Xiao Ming go to a movie theater 2400 meters away from school to watch a movie. Xiao Cong walked 60 meters per minute, Xiao Ming started 10 minutes after he set off, and they both arrived at the theater at the same time, how many meters did Xiao Ming walk per minute?
小聪和小明从学校到相距2400米的电影院去看电影．小聪每分钟行60米，他出发后10分钟小明才出发，结果俩人同时到达影院，小明每分钟行多少米．
<gadget id="calculator">2_400 / 60</gadget>
<output>40</output>

<gadget id="calculator">40 - 10</gadget>
<output>30</output>

<gadget id="calculator">2_400 / 30</gadget>
<output>80</output>

<result>80</result>