Task: Question Answering
Input (English): Problem: for the past n days , the average ( arithmetic mean ) daily production at a company was 50 units . if today ' s production of 110 units raises the average to 55 units per day , what is the value of n ? 
Options: a ) 9 , b ) 11 , c ) 13 , d ) 15 , e ) 17
Output (English): b