Xiao Ming's father drives from place A to place B, traveling an average of 84 kilometers per hour and arriving in 5 hours. It took 4 hours to return, what was the speed of return?
小明的爸爸开车从甲地到乙地，平均每小时行84千米，5小时到达．返回时用了4小时，返回的速度是多少？
<gadget id="calculator">5 / 4</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">84 * (5/4)</gadget>
<output>105</output>

<result>105</result>