In a mountain climbing competition, Xiaogang walked 40 meters per minute when going up the mountain, and reached the top of the mountain in 18 minutes. Then go down the mountain on the same road, walking 60 meters per minute. How many meters per minute did Xiaogang walk up and down the mountain on average?
在一次登山比赛中，小刚上山时每分走40米，18分到达山顶．然后按原路下山，每分走60米．小刚上、下山平均每分走多少米？
<gadget id="calculator">40 * 18 * 2</gadget>
<output>1_440</output>

<gadget id="calculator">40 * 18</gadget>
<output>720</output>

<gadget id="calculator">720 / 60</gadget>
<output>12</output>

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

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

<result>48</result>