Xiaohong goes to work from place A to place B 1200 meters away, walking 40 meters per minute when going, and 60 meters per minute when returning. The average speed of Xiaohong back and forth is how many meters per minute.
小红从甲地到1200米外的乙地去办事，去时每分钟走40米，返回时每分钟走60米．小红往返的平均速度是每分钟走多少米．
<gadget id="calculator">1_200 * 2</gadget>
<output>2_400</output>

<gadget id="calculator">1_200 / 40</gadget>
<output>30</output>

<gadget id="calculator">1_200 / 60</gadget>
<output>20</output>

<gadget id="calculator">30 + 20</gadget>
<output>50</output>

<gadget id="calculator">2_400 / 50</gadget>
<output>48</output>

<result>48</result>