The art group sketched along a 2160-meter-long mountain road, and then returned from the original road. It walked up the mountain for 36 minutes and down the mountain for 24 minutes. Find the average number of meters the art group walked up and down the mountain per minute.
美术小组沿着一条长为2160米的山路上山写生，又从原路返回，上山时走了36分钟，下山走了24分钟，求这个美术小组上、下山平均每分钟走多少米．
<gadget id="calculator">36 + 24</gadget>
<output>60</output>

<gadget id="calculator">2 / 60</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">2_160 * (1/30)</gadget>
<output>72</output>

<result>72</result>