Task: Question Answering
Input (English): Problem: the first flight out of phoenix airport had a late departure . if the next 3 flights departed on - time , how many subsequent flights need to depart from phoenix on - time , for the airport ' s on - time departure rate to be higher than 40 % ? 
Options: a ) 4 , b ) 6 , c ) 5 , d ) 2 , e ) 8
Output (English): d