The lines are intersecting and the spaces that don't have angles like for instance find the value of x. X looks like its the exact same as the angle right in left side of it, same with top and bottom.
They will be at exactly 80 miles because the train going from Manhattan to jersey and the train going from Jersey to Manhattan meet at 80 because 60 is the halfway stop and the train going from Jersey is 20 mph more. Therefore, 80 mph is the answer