Task: Question Answering
Input (English): Problem: mark and ann together were allocated n boxes of cookies to sell for a club project . mark sold 9 boxes less than n and ann sold 2 boxes less than n . if mark and ann have each sold at least one box of cookies , but together they have sold less than n boxes , what is the value of n ? 
Options: a ) 9 , b ) 10 , c ) 11 , d ) 12 , e ) 13
Output (English): b