Xiao Ming and Xiao Liang set off from the school and library that are 1800 kilometers apart at the same time, and walk towards each other. If they keep walking at a speed of 80 meters per minute and then 100 meters per minute, how many minutes will they meet?
小明与小亮同时从相距1800千米的学校和图书馆出发，相对而行．如果他们依次保持每分80米和每分100米的速度行走的话，那么几分钟后就能相遇？
<gadget id="calculator">80 + 100</gadget>
<output>180</output>

<gadget id="calculator">1_800 / 180</gadget>
<output>10</output>

<result>10</result>