Task: Question Answering
Input (English): Problem: a driver goes on a trip of 60 kilometers , the first 30 kilometers at 48 kilometers per hour and the remaining distance at 24 kilometers per hour . what is the average speed of the entire trip in kilometers per hour ? 
Options: a ) 30 , b ) 32 , c ) 36 , d ) 40 , e ) 42
Output (English): b