Task: Question Answering
Input (English): Problem: susan drove an average speed of 30 miles per hour for the first 40 miles of a trip then at a average speed of 15 miles / hr for the remaining 40 miles of the trip if she made no stops during the trip what was susan ' s avg speed in miles / hr for the entire trip 
Options: a ) 35 , b ) 20 , c ) 45 , d ) 50 , e ) 55
Output (English): b