A train travels from New York to Chicago, a distance of approximately 840 miles, at an average rate of 60 miles per hour and arrives in Chicago at 6:00 in the evening , Chicago time. At what hour in the morning, New York City time, did the train depart for Chicago time. At what hour in the morning , New York City time, did the train depart for Chicago? ( Chicago time is one hour earlier than New York City time.)