What are Factorials, Permutations, and Combinations?

[939]

Homework Statement

I am asked "evaluate the following factorials, permutations, and combinations". I am given a series of questions I understand, like P(10,3), 9!, etc. But then I have a series like this:

Homework Equations

The Attempt at a Solution

I am not sure what this is, is it a combination, perhaps because there hasn't been any yet, and this is solved by 25C5?

 

[Bacle2]

I'm not sure what you mean by a series, but usually , yes, it is 25C5.

 

[939]

I'm not sure what you mean by a series, but usually , yes, it is 25C5.

Sorry, I ment a list, as in I have 10 questions, with a few looking like the one on the photo, a few looking like 9!, and a few looking like p(10,3). =)

 

[Bacle2]

Oh, O.K, makes sense, maybe I was kind of thick.