OG数学SQ 136求助

rita0316

题是这样滴~~
a train travels from New York City to Chicago,a distance of approximately 840miles,at an average rate of 60 miles per hour and arrives in Chicago at 6:00in the evening.At what hour in the morning,New York City time,did the train depart for Chicago?(Note:Chicago time is one hour earlier than New York time.)
我算出来了始发时间是Chicago time 4:00am,but the answer is 5:00am in New York time ,why not 3:00am in New York time ?

yaner11

Chicago time is one hour earlier than New York time。
就是芝加哥是4点的话，纽约就是5点。