The distance from the bottom of the mountain to the top of the mountain is 1200 meters. Xiaohua’s average speed is 60 meters per minute when going up the mountain, and 120 meters per minute when going down the mountain. What is the average speed of Xiaohua’s round trip in meters per minute?
从山下到山上的路程是1200米，小华上山时平均速度为每分钟走60米，下山时平均每分钟走120米，则小华往返行程中的平均速度是每分钟走多少米．
<gadget id="calculator">1 + 1</gadget>
<output>2</output>

<gadget id="calculator">1 / 60</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">1 / 120</gadget>
<output>1/120 = around 0.008333</output>

<gadget id="calculator">(1/60) + (1/120)</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">2 / (1/40)</gadget>
<output>80</output>

<result>80</result>