Task: Question Answering
Input (English): Problem: 3 positive integers a , b , and c are such that their average is 20 and a ≤ b ≤ c . if the median is ( a + 13 ) , what is the least possible value of c ? 
Options: a ) 21 , b ) 22 , c ) 23 , d ) 24 , e ) 25
Output (English): e