Task: Question Answering
Input (English): Problem: a car averages 55 mph for the first 4 hours of a trip and averages 70 mph for each additional hour . the average speed for the entire trip was 60 mph . how many hours long is the trip ? 
Options: a ) 6 , b ) 8 , c ) 11 , d ) 12 , e ) 14
Output (English): a