During the "May 1st" period, the three members of Xiaohua's family went to climb the mountain. When going up the mountain, they walked 75 meters per minute, and went back down the mountain by the same way. It took 3 minutes longer than going up the mountain. It is known that the foot of the mountain is 2700 meters from the top of the mountain. Find their average speed of going up and down the mountain ．
"五一"期间，小花家三口去爬山，上山时每分钟走75米，下山原路返回，用的时间比上山多了3分钟，已知山脚到山顶2700米，求他们上下山的平均速度．
<gadget id="calculator">2_700 / 75</gadget>
<output>36</output>

<gadget id="calculator">36 + 3</gadget>
<output>39</output>

<gadget id="calculator">36 + 39</gadget>
<output>75</output>

<gadget id="calculator">2 / 75</gadget>
<output>2/75 = around 0.026667</output>

<gadget id="calculator">2_700 * (2/75)</gadget>
<output>72</output>

<result>72</result>