If each of the digits 2, 3, 4, 6, 7, and 8 is used exactly once to construct two 3-digit numbers m and n, what is the smallest possible positive value of the difference m - n ?
Marco's average score for all 14 quizzes this semester was 81. If Marco had an average score of 75 for his first 10 quizzes this semester, what was the average score for his last four quizzes?
The median of an ordered set of 11 integers is 35. In this set, the median of the first five integers is 29, and the median of the last 5 integers is 39. If the minimum and maximum values of the set are 12 and 52, respectively, what is the greatest possible value of the mean of this set?