An alphagram is a string of letters, such as ABC or AABEGLR, whose letters are in alphabetical order. Find the number of four-letter alphagrams.
1 - Without repeating the letters, you have: 26 nCr 4 =14,950 alphagrams.
2 - If each letter can be repeated up to 4 times, then you have: [26 + 4 - 1] nCr 4 =23,751 alphagrams.
