Currently, each student in our school system is assigned a 6-digit (each
digit is 0-9) student identification number.
As the school system plans for the future, they are considering using a 7th
character, that will be a letter (each letter can be A-Z).
Use the counting principle to determine how many unique student
identification codes can be created with these 7 characters (1 letter
followed by 6 digits).