How many distinguishable permutations can be made using "SEATTLE". Please explain how to do it because I need to know how to do these.

Question

anonymous · Answer

just a factorial, but not counting the doubles of the number?

anonymous · Answer

I think so because the problem says distinguishable.

anonymous · Answer

$$\frac{7!}{(2!)(2!)    }=210 $$

anonymous · Answer

I understand the 7! part, but why would (n - r)! be 2?

anonymous · Answer

This is a math team question, so they gave me the answers, but not the explanations.

anonymous · Answer

Btw, the answer is supposed to be 1260. How do I get that?

anonymous · Answer

There are total 8 letters out of which the letters T and E are repeated twice. So the total number of permutations is divided by the permutations of the repeated elements.

anonymous · Answer

7 letters, that is.

anonymous · Answer

Ok.But you got 210. It's supposed to be 1260.

anonymous · Answer

kk

anonymous · Answer

just a typo. thats all.