Question

What is the total number of different nine-letter arrangements that can be formed using the letters in the word "tennessee"?

Answer 1

If there are n objects where A of them are alike, another B of them are alike, and so on, then the total number of permutations = n! / [(A!)(B!)...]

n=9
There are 4 identical E's
2 identical N's
2 identical S's

So the number of possible arrangements = 9! / (4!)(2!)(2!) = 3780.