In a mountaineering competition, Kobayashi walked up the mountain 40 meters per minute, reached the top of the mountain in 18 minutes, and then went down the mountain by the same route, which took 12 minutes. How many meters per minute did Kobayashi walk up and down the mountain on average?
在一次登山比赛中，小林上山每分钟走40米，18分钟到达山顶，然后按原路下山，用了12分钟．小林上山、下山的全过程平均每分钟走多少米？
<gadget id="calculator">40 * 18 * 2</gadget>
<output>1_440</output>

<gadget id="calculator">18 + 12</gadget>
<output>30</output>

<gadget id="calculator">1_440 / 30</gadget>
<output>48</output>

<result>48</result>