Mississipi Counting Problem?

1. Find the number of ways the letters in Mississipi can be arranged in groups of three. 2. Find the general formula for a group g letters. 3. For any given word with l letters labeled from 1 to l and these l letters appear n1, n2, n3, ..., nl times respectively, find the total number of ways to arrange... show more 1. Find the number of ways the letters in Mississipi can be arranged in groups of three.

2. Find the general formula for a group g letters.

3. For any given word with l letters labeled from 1 to l and these l letters appear n1, n2, n3, ..., nl times respectively, find the total number of ways to arrange these letters in groups of g letters.

Don't do all of them if you don't want to.
Update: I think I'll have to rephrase #3. Hopefully you guys still get the idea.
Update 2: If this were the common combination problem, I wouldn't have asked...

Mississipi repeats its letters many times. What is the way to deal with this?
Update 3: Only just a group of 3.
MIS is one group of 3.

I want to know how many different ways we can do this using all the letters.
Update 4: - -, are you sure it works? I don't think it works for g = 11.
Also, what is your name? Calling people by dashes is inhumane.
Update 5: Dang, what's the correct spelling for Mississipi?
g = 10 doesn't work either.
Update 6: My teacher showed us these questions that he had a problem with. He managed to do #1, but not #2. I added #3 for fun.
Update 7: My teacher didn't use generating functions. The normal way. He used combinations and counting principles.
Update 8: Drat, I see now. - -, you're misunderstanding the problem. Although g = 10, you can rearrange the letters inside it.

For example:
Mipssissii is an example of a group.
Update 9: Can you explain to me why these coefficients represent this permutation of letters?
What about anything different from 10 letters? How can we find these generating functions?
Update 10: Oops, too careless of me. You did give an answer to one of my questions in my additional details. Sorry!
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