Definition: The task is to generate the correct answer for a given math problem.
Input: Problem: a train travels from new york to chicago , a distance of approximately 540 miles , at an average rate of 60 miles per hour and arrives in chicago at 6 : 00 in evening , chicago time . at what hour in the morning , new york time , did the train depart for chicago ? ( note : chicago time is one hour earlier than new york time )
