Question

Solve the permutation.

11 P 9 / 11 P 8

Answer 1

simplify

Answer 2

do you know what is permutation?

Answer 3

Yeah, I think. like for the 11 P 9, you would do: 11*10*9 right?

Answer 4

no

Answer 5

\[11\text{ P }9=\frac{11!}{2!}\] yes?

Answer 6

Yeah, I understand so far.

Answer 7

isn't that factorial?

Answer 8

yes. and also
\[11\text{ P }8=\frac{11!}{3!}\] so when you divide, invert and multiply

Answer 9

11! = 11*10*9*8*7*6*5*4*3*2*1?

Answer 10

\[nPk=\frac{n!}{(n-k)!}\] that's formula for permutations

Answer 11

so you get a huge cancellation are are left with very little

Answer 12

thomas.a wrote the formula, i used the numbers.
you are dividing one by the other.
invert and multiply
cancel the 11! and then see what you get

Answer 13

11! / 2! = 19958400?

Answer 14

i know that you did but i wrote in general form and it's explained how you got denominator

Answer 15

you should do like satellite advised

Answer 16

k

Answer 17

whenever you are dealing with factorials, cancel first, multiply last

Answer 18

Cancel 11!?

Answer 19

yes. there is one in the numerator and one in the denominator.
out they go

Answer 20

okay so 11! is no longer there. Just 2!, and then 3!?

Answer 21

\[\frac{11!}{2!}\div \frac{11!}{3!}=\frac{11!}{2!}\times \frac{3!}{11!}\]

Answer 22

and just to confirm, 11! would mean you do this math?: 11*10*9*8*7*6*5*4*3*2*1

Answer 23

that is the meaning of 11! yes

Answer 24

but in this case you do no such thing. just cancel them to get
\[\frac{3!}{2!}=\frac{3\times 2}{2}=3\]

Answer 25

So all you do to find this answer is find 11! * 3!, and 2! * 11, then divide the two large numbers?

Answer 26

cancel cancel cancel.
\[\frac{11!}{11!}=1\]

Answer 27

okay i got it now. thanks.