A train travels 800 kilometers at night and 160 kilometers at the same speed in the morning, and travels 8 hours longer at night than in the morning. What is the speed of this train in kilometers?
一列火车夜间行驶了800千米，上午以同样的速度行驶了160千米，夜间比上午多行了8小时．这列火车的速度是多少千米？
<gadget id="calculator">800 - 160</gadget>
<output>640</output>

<gadget id="calculator">640 / 8</gadget>
<output>80</output>

<result>80</result>