# Thread: Permutation and combination doubt?

1. ## Permutation and combination doubt?

I have learned that permutation deals with arrangement and order while combination deals with arrangement but the order is not important.
I understand the definition but when a question comes I can't distinguish which formula to use either permutation or combination :'(

example
in how many ways can 5 starting position on a NBA team be filled with 12 men who can play any of the position?

(What is it and what shall I use? And how to distinguish permutation and combination question really feeling confused ?

2. Originally Posted by mj.alawami
I have learned that permutation deals with arrangement and order while combination deals with arrangement but the order is not important.
I understand the definition but when a question comes I can't distinguish which formula to use either permutation or combination :'(

example
in how many ways can 5 starting position on a NBA team be filled with 12 men who can play any of the position?

(What is it and what shall I use? And how to distinguish permutation and combination question really feeling confused ?
The order you list your five players does not matter so you use permutations.

12 times 11 times 10 times 9 times 8 =

If, on the other hand, you were looking at the number of ways you can sit five people around a dining table then you would use combinations.

Hope this helps!

3. Originally Posted by apcalculus
The order you list your five players does not matter so you use permutations.

12 times 11 times 10 times 9 times 8 =

If, on the other hand, you were looking at the number of ways you can sit five people around a dining table then you would use combinations.

Hope this helps!
in permutation isn't order important and in combination it isn't. So why are your definition the wrong way round

4. the other way around, of course.