From home to school, he travels an average of 12 kilometers per hour when he goes there, and arrives in (2/3) hours. It takes only (1/2) hour to return home from school. How many kilometers per hour is the average travel time when he returns?
从家到学校，去时平均每小时行12千米，(2/3)小时到达，放学回家原路返回时只用了(1/2)小时，返回时平均每小时行多少千米？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(2/3) / (1/2)</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">12 * (4/3)</gadget>
<output>16</output>

<result>16</result>