Xiao Ming and his elder brother set off from home to the park at the same time. The elder brother rides a bicycle while Xiao Ming walks. When the elder brother arrives at the park 10 minutes later, Xiao Ming is still 1200 meters away from the park. It is known that my brother's cycling speed is three times that of Xiao Ming's walking speed. How many meters does Xiao Ming walk per minute?
小明与哥哥两人同时从家出发去公园，哥哥骑自行车，小明步行，10分钟后哥哥到公园时，小明距离公园还有1200米．己知哥哥骑车的速度是小明步行速度的3倍．小明步行每分钟走多少米？
<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<gadget id="calculator">1 * 10</gadget>
<output>10</output>

<gadget id="calculator">30 - 10</gadget>
<output>20</output>

<gadget id="calculator">1_200 / 20</gadget>
<output>60</output>

<result>60</result>