When a truck travels from City A to City B, it travels an average of 84 kilometers per hour and arrives in 5 hours. It took 4 hours to return, how many kilometers per hour on average when returning?
一辆货车从甲城去乙城时，平均每小时行84千米，5小时到达．返回时用了4小时，返回时平均每小时行多少千米？
<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>