Circular permutation = (n-1)!
= 4!
= 24
Answer C

circulation permutation- n!/n

5!/5=24

C

Thanks

thanks both of you!

Please, help

for circular permutation. How do we have

(N-1)!

duongthang wrote:Please, help

for circular permutation. How do we have

(N-1)!

good explanation is provided here.Please check
https://www.beatthegmat.com/circular-per ... tml#241159

duongthang wrote:Please, help

for circular permutation. How do we have

(N-1)!

Say we want to arrange A B C in normal permutation

ABC ACB BAC BCA CAB CBA - There are 6 ways to arrange A B C

or n! ways (n being 3)

Now in a circular permutation ABC, BCA and CAB are the same
Also ACB, CBA and BAC are the same (because it is circular and hence the start and the end doesnt matter the order matters)

There are only 2 permuations

or (n-1)! (n being 2)

That's one way to explain why (n-1)!

When you arrange n objects linearly you have n!
When you arrange them in a circular fashion, that time abc is the same thing as cba when n = 3.
In general you will have n number of redundancies because of circular perm.

Hence for circular = n!/n = (n-1)!