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 ?
"if n = 10 mark sold 1 box and ann sold 8 boxes total 9 < 10 answer : b"
add(9, const_1)