On Sunday, Xiaoli's family went for an outing. It took 2 hours to go, and the speed was 75 kilometers per hour; it took 3 hours to return, how many kilometers per hour on average when returning?
星期天小丽一家去郊游，去时用了2小时，速度是75千米∕时；返回时用了3小时，返回时平均每小时行多少千米？
<gadget id="calculator">75 * 2</gadget>
<output>150</output>

<gadget id="calculator">150 / 3</gadget>
<output>50</output>

<result>50</result>