Teacher Wang drove back to his hometown to visit relatives. He traveled 60 kilometers per hour and arrived at 5 o'clock; when he returned, he only took 4 o'clock to arrive. How many kilometers per hour did Mr. Wang travel when he returned?
王老师开车回老家探亲，去时每时行60千米，用了5时到达；返回时只用了4时就到达了．王老师返回时每时行多少千米？
<gadget id="calculator">5 / 4</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">60 * (5/4)</gadget>
<output>75</output>

<result>75</result>