Alfred wants to become a member of an online discussion forum. The website requires him to create a password. The password must consist of 5 characters, of which 3 must be letters and 2 must be digits. The first character of the password must be a letter. Also, repetition of the same letter in the password is not permitted but repetition of digits is permitted. How many possible ways can Alfred create the password? So I know the answer is 9,360,000 but I got 18,720,000. This is because I thought the partition is 4! / (2! * 1! * 1!) but apparently the partition is 4! / (2! * 2!) and this confuses me. I thought that since the letters can't be repeated, we'd put one unique letter in one group, the other unique letter in the other group, and the two repeated digits in the last group. Can somebody explain this to me?