A train travels from New York to Chicago, a distance of approximately

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 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)

A. 3:00
B. 4:00
C. 5:00
D. 6:00
E. 7:00

It's a bit ambiguous as to what exactly "Chicago time is one hour earlier" actually means. Does it mean that it's "earlier" there, by one hour - in which case the time in NY is 7 PM - or does it mean that chicago time is "earlier"/faster than NY time by one hour (in which case the clock is 5PM in NY). In fact, the info specifically refers to Chicago time being one hour earlier (what does that even mean? For time to be earlier? Extremely poor choice of words), this creates ambiguity.

Of course, common sense tells us that geographically, Chicago is to the west of NY so the second scenario doesn't make sense, but if we don't use "common" wordly sense, we could eroneously conclude that A - 3:00 is the correct answer. Which, of course, it's not.

And since the GMAT doesn't test skills in geography, being punished for not knowing where different cities in the US are located is pretty much laughable.


For instance: "Sprinter X finished earlier than sprinter Y" means that sprinter X is faster than Y, which means that it takes sprinter Y longer to arrive at the finish line than it takes sprinter X. Apply this logic to time zones for NY and Chicago: "Chicago time is earlier than NY time", this means that it takes NY time longer to arrive at the same time than it takes Chicago. So if it's 6PM in Chicago, NY will be at 6PM in one hour, which means it's 5PM in NY right now.


But this is not the first time that I feel like GMAT uses vague wording, it's very annoying.