Task: Question Answering
Input (English): Problem: jerry began driving from home on a trip averaging 30 miles per hour . how many miles per hour must carla drive on average to catch up to him in exactly 3 hours if she leaves 30 minutes after jerry ? 
Options: a ) 35 , b ) 55 , c ) 39 , d ) 40 , e ) 60
Output (English): a