A car goes up the mountain at 36 kilometers per hour. It takes 5 hours to reach the top of the mountain. How many kilometers per hour does the car travel on average when going downhill?
一辆汽车上山每小时行36千米，行了5小时到达山顶，下山时按原路返回，提前了1小时．汽车下山时平均每小时行多少千米？
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">5 / 4</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">36 * (5/4)</gadget>
<output>45</output>

<result>45</result>