A passenger plane flew from Beijing to Harbin at 11:30 am and arrived in Harbin at 13:30 pm. Given that the distance between Beijing and Harbin is 3,980 kilometers, how many kilometers does this passenger plane fly on average per hour?
一架客机上午11：30分从北京飞往哈尔滨，下午13：30分到达哈尔滨．已知北京到哈尔滨两城间的距离是3980千米，这架客机平均每小时飞行多少千米？
<gadget id="calculator">3_980 / 2</gadget>
<output>1_990</output>

<result>1_990</result>