A car travels from city A to city B at 72 kilometers per hour and arrives in 16 hours. When returning, it took 18 hours to reach City A, so how many kilometers per hour does the car travel from City B to City A on average?
一辆汽车从甲城开往乙城，每小时行72千米，16小时到达．返回时，用了18小时到达甲城，那么这辆汽车从乙城返回甲城平均每小时行多少千米？
<gadget id="calculator">16 / 18</gadget>
<output>8/9 = around 0.888889</output>

<gadget id="calculator">72 * (8/9)</gadget>
<output>64</output>

<result>64</result>