The students went to climb the mountain. When going up the mountain, they walked 40 meters per minute. It took 15 minutes. Then they went down the mountain by the same way and took 10 minutes. Please calculate how many meters per minute the students walked on average when going up and down the mountain?
同学们去爬山，上山时每分钟走40米，用了15分钟，然后按原路下山，用10分钟，请算一算同学们上下山时平均每分钟走多少米？
<gadget id="calculator">15 + 10</gadget>
<output>25</output>

<gadget id="calculator">2 / 25</gadget>
<output>2/25 = around 0.08</output>

<gadget id="calculator">40 * 15 * (2/25)</gadget>
<output>48</output>

<result>48</result>