Xiaohong has 120 meters from home to school, and walks 40 meters per minute when going to school. When returning home, she walks 60 meters per minute. What is the average speed of Xiaohong going back and forth from home to school in meters per minute?
小红从家到学校有120米，去学校时每分走40米．返回家时每分走60米，小红从家到学校往返的平均速度是每分多少米？
<gadget id="calculator">1 / 40</gadget>
<output>1/40 = around 0.025</output>

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

<gadget id="calculator">(1/40) + (1/60)</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">2 / (1/24)</gadget>
<output>48</output>

<result>48</result>