Question

evaluate P(6,2)

Answer 1

You mean permutations ? like 6 P 2 (an nPr) ?

Answer 2

premutations

Answer 3

\(\Large\color{red}{ \rm _6~P~_2 = }\) \(\LARGE\color{blue}{ \rm \frac{6!}{(6-2)!} }\)

Answer 4

\(\LARGE\color{blue}{ \rm = \frac{6!}{4!}=\frac{4! \times 5 \times 6}{4!} }\)

Answer 5

so it would be 4?

Answer 6

Cab you finish the problem from here ?

Answer 7

Can you ... ?

Answer 8

no

Answer 9

Okay, So, do you know what `6!` and `4!` is ?

Answer 10

not really

Answer 11

\(\large\color{red}{ \bf 7! =1\times2\times3\times4\times 5 \times 6 \times7 }\)

\(\large\color{red}{ \bf 5! =1\times2\times3\times4\times 5 }\)

\(\large\color{red}{ \bf 9! =1\times2\times3\times4\times 5 \times 6 \times7\times8 \times9 }\)

this is the meaning behind the exclamation mark here. Get it?

Math-wise,

\(\large\color{red}{ \bf n! =1 \times 2 \times ~~....~~(n-1) \times n }\)

Answer 12

yeah

Answer 13

So

\(\large\color{blue}{ \rm 6!=1\times2\times 3 \times 4 \times 5 \times 6 }\)

AND therefore,

\(\large\color{blue}{ \rm 6!=(4!) \times 5 \times 6 }\)

COrrect ?

Answer 14

coorect

Answer 15

*correct

Answer 16

So, in permutation labeled as ` n P r ` you are choosing r (things) out of n (things).
The order matters (as opposed to combinations labeled with ` n C r ` )

Saying that 1,2,3,4 would NOT be the same as 1,3,2,4 when it comes to permutations.

The formula is

\(\LARGE\color{blue}{ \rm nPr= \frac{n!}{(n-r)!} }\)

Answer 17

In your case you have

\(\LARGE\color{blue}{ \rm 6~P ~2 }\)

Answer 18

So,

\(\LARGE\color{blue}{ \rm 6~P~2= \frac{6!}{(6-2)!} }\)

Answer 19

Now you just need to simplify it,

\(\LARGE\color{blue}{ \rm 6~P~2= \frac{6!}{(6-2)!} }\)


\(\LARGE\color{blue}{ \rm 6~P~2= \frac{6!}{4!} }\)

Lets re-write ` 6! ` on the top.

\(\LARGE\color{blue}{ \rm 6~P~2= \frac{4! \times 5 \times 6}{4!} }\)

\(\LARGE\color{blue}{ \rm 6~P~2= \frac{4! \times 30}{4!} }\)

` 4! ` cancel.

\(\LARGE\color{blue}{ \rm 6~P~2= 30 }\)

Answer 20

Makes sense ? (tell me when you go over what I typed ...) :)

Answer 21

yes makes since thank you so much! :)n

Answer 22

i actually know what im doing now thanks