Question: A bookstore displays a shelf of 5, 3, and 4 copies, respectively, of the top 3 bestsellers. How many distinguishable arrangements of these books are there if books with the same title are not distinguishable?
The United Group for Divisive Action uses secret code words that are permutations of 5 characters. You learn that there are only 10 code words. What can you say about repeated characters in the code words?