Perms and combs question (1 Viewer)

[enigma_1]

Find no. of arrangements in the letters of SLOOPS if the 2 Os are together.

I did this a while ago and I don't understand my working out. What exactly is the logic in this question?

 

[enigma_1]

I did 5! / 2!.

I sorta get it, but can someone just remind me lol please

 

[braintic]

Treat the Os as a block which must remain together.

So the letters/blocks to be shuffled are (S), (S), (L), (P), (OO)

So 5!/2! is correct, allowing for the two S's.

 

[enigma_1]

Treat the Os as a block which must remain together.

So the letters/blocks to be shuffled are (S), (S), (L), (P), (OO)

So 5!/2! is correct, allowing for the two S's.

Thanks heaps!

 

[braintic]

Thanks heaps!

Note that if it were two different (but non-repeated) letters that had to remain together (so L and P), the calculation would be:

(S) (S) (O) (O) (LP)

the calculation would be 5! / (2!.2!) times 2!, since the L and P can be swapped within their group.

So ... same answer