Question

What is the value of 12C4?

A.
48

B.
3

C.
495

D.
11,880

Answer 1

@amistre64 Do you think you could help me with this?

Answer 2

what is 12 P 4?

Answer 3

12 C 4 = 12 P 4, divided by 4!

Answer 4

I dont undertand.

Answer 5

then you most likely have not reviewed your course materials enough

Answer 6

Its either that or Im tired for doing 4 other lessons, I got 100% on those but I just dont understand that one part wich got me 79% this is my second attempt, ITs just this one stupid problem

Answer 7

12C4 = C(12,4)
C(n,r) = n! / [(n - r)! r!]
C(12,4) = 12! / [(12 - 4)! r!]
C(12,4) = 12! / (8! 4!)
C(12,4) = 12 * 11 * 10 * 9 / (4 * 3 * 2) = 990/2 = ?

Answer 8

how have you tried to work it?

Answer 9

would I do, 12*11*10
4*3*2*1?

Answer 10

It's easiest if you simplify these first. In the numerator, all but the r highest numbers cancel, leaving you with what I showed. 12 and 4 * 3 canceled leaving you with 11 * 90 = 990 and 2

Answer 11

pick 4, not 3

12.11.10.9
---------
4.3.2.1

then simplify yes

12 and 2

Answer 12

@samman8801 do you know how to divide?

Answer 13

So I get 11880? Then simplify that,
And yes

Answer 14

then divide 990/2 is......

Answer 15

12.11.10.9
---------
4.3.2.1



11.10.9
-------
2




11.5.9


it tends to simplify itself out to start with

Answer 16

11880 = 12 P 4

divide it by 4.3.2.1 = 24

Answer 17

OHHHHHHHH, Ok I understand this now

Answer 18

it is rather elementary :) the notation is always a looper tho

Answer 19

So my answer is 495?