Xiaoyu's family went for an outing on Sunday, and it took 4 hours to go at a speed of 60 kilometers per hour; it took 2 hours to return. What is their average speed round trip?
星期天小玉一家去郊游，去时的速度是每时60千米，用了4时；返回时用了2时．他们往返的平均速度是多少？
<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<gadget id="calculator">2 / 6</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">60 * 4 * (1/3)</gadget>
<output>80</output>

<result>80</result>