Combination or permutation?

[jcoutts]

This may be a really simple question, but I can't figure it out to be certain I am right. Any help would be appreciated.

If I have an article consisting of 1 headline and 7 paragraphs, I therefore have 8 elements making up the article.

If I create 3 different versions of each element (3 headlines and 3 different paragraphs for each of the 7 paragraphs), I have 24 parts all together.

My question is: how many different ways can I combine those parts so they stay in order?

That is, the article starts with any 1 of the 3 versions of the headline, followed by any 1 of the 3 versions of the 1st paragraph, and so on until the last or 7th paragraph, in strict order.

I first thought it would be 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 = 6,561, but that is a combination of all possible ways, I'm now thinking. Perhaps it's a permutation instead? I don't know ...

Does anyone know?

John.

 

[pka]

If I have an article consisting of 1 headline and 7 paragraphs, I therefore have 8 elements making up the article. If I create 3 different versions of each element (3 headlines and 3 different paragraphs for each of the 7 paragraphs), I have 21 parts all together.
My question is: how many different ways can I combine those parts so they stay in order?
I first thought it would be 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 = 6,561 .

That is correct.
Why do you think it is not?

 

[jcoutts]

That is correct.
Why do you think it is not?

OK, thanks for that. I appreciate it.

I was trying to check it through Google, and I came up with things about permutations and combinations. The difference seems to be that a permutation is used when things have to stay in order, and that got me thinking I might be wrong in my calculations. I just wanted to be sure.

John

 

[Amom123]

I use this mnemonic device to remember the difference. A Combination lock should be named a Permutation lock because we do need the numbers to be in a specific order, or we cannot unlock the answer.