This time the train traveled 640 kilometers in total. In the first 3 hours, it traveled a total of 240 kilometers. The remaining distance traveled an average of 80 kilometers per hour. How many hours did it take to complete the journey?
本次列车全程运行640千米，前3小时共行了240千米，剩下的路程平均每小时行80千米，行完全程共用几小时？
<gadget id="calculator">640 - 240</gadget>
<output>400</output>

<gadget id="calculator">400 / 80</gadget>
<output>5</output>

<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<result>8</result>