Xiao Zheng goes to the cinema, and the distance from home to the cinema is 1500 meters. In the afternoon, it took him 25 minutes to go from home to the cinema. After watching the movie, it also took him 25 minutes to get home from the cinema. Find the average speed of Xiao Zheng’s round trip.
小郑去看电影，从家到电影院有1500米，下午他从家里出发到电影院用了25分钟，看完电影，他从电影院到家也用了25分钟，求小郑往返的平均速度．
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">2 / (5/6)</gadget>
<output>12/5 = around 2.4</output>

<gadget id="calculator">1_500 * (12/5)</gadget>
<output>3_600</output>

<result>3_600</result>