## anonymous one year ago Find the number of permutations of the first 12 letters taken 3 at a time.

12 letters of the alphabet I assume?

2. anonymous

I guess because that's all it says

$\frac{ n! }{ (n-r)! }$ Is the equation you want.

4. dan815

does permutations means u arent allowed to repeat letters

5. dan815

you have 12 letters, and you want to pick 3 of them you hae 12 choices for the first letter you pick, leaving you with any one of the 11 other choices leaving you with 10 other choices 12*11*10

6. dan815

|dw:1435214436754:dw|

7. dan815

|dw:1435214481676:dw|

Using this equation, I got 1320.

9. anonymous

I got 1320?

10. dan815

and then there will be another 10 for eeach of the paths on the 2nd pick, thats why we multiply 12*11*10

11. dan815

ya thats right

12. anonymous

Thank you <3