Task: Question Answering
Input (English): Problem: a basketball is dropped from a height of 20 feet . if it bounces back up to a height that is exactly half of its previous height , and it stops bouncing after hitting the ground for the fourth time , then how many total feet will the ball have traveled after 2 full bounces . 
Options: a ) 50 , b ) 55 , c ) 60 , d ) 75 , e ) 100
Output (English): e