Uncle Wang rode a motorcycle from home to the county to listen to lectures on agricultural science and technology. Departure at 8:30, arrive at the county seat at 10:30, the speed is 24 km/h. Return at 15:00, arrive home at 18:00, what is the average speed of Uncle Wang's return?
王叔叔骑摩托车从家到县城听农业科技讲座．8：30出发，10：30到县城，速度是24千米/小时．15：00返程，18：00到家，王叔叔返程的平均速度是多少？
<gadget id="calculator">30 / 10</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">24 * (2/3)</gadget>
<output>16</output>

<result>16</result>