Problema Solution

Two trains left Salt Lake City, one heading east the other heading west. The first train is traveling at 60 mph. When will the two trains be 400 miles apart?

Answer provided by our tutors

The problem statement is ambiguous because no information contains relative speed.  If both trains are travelling at the same speed then both are travelling at 60 mph, so we'll assume that. 

400/(60+60)

click here to simplify

3.3333

So based on the assumption, they will be 400 miles apart after 3 1/3 hours.