+0  
 
+2
46
10
avatar+189 

Can someone explain it plz

 May 1, 2020
 #1
avatar+656 
+1

To calculate the number of happening of an event, N chooses K tool is used. N is the sum of data and K is the number that we chose from the sum of data.

The formula for N choose K formula is

:\(C(n, k)= n!/[k!(n-k)!] \)Where,
n is the total number
k is the number of selected item

Solved Examples

Question 1: How many ways to draw exactly 6 cards from a pack of 10 cards?

Solution:

From the question, it is clear that,
N = 10
N = 6

So the formula for n choose k is,\(C(n, k)= n!/[k!(n-k)!] 610C=10!6!(10−6)!=362880017280 \)= 210

So, there are 210 ways of drawing 6 cards in a pack of 10.

 

This formula and topic is very useful in solving various types of problems I recommend that you you practice this topic until you feel like you can solve and N choose K question.

 

Here to help

:D

 May 1, 2020
 #2
avatar+189 
0

So then whats..

 

0 choose 0

 

1 choose 1

 

-1 choose 1

SoggyPerson  May 1, 2020
 #3
avatar+656 
0

I belive it would be

 

0 choose 0 = 1

 

1 choose 1 = 1

LuckyDucky  May 1, 2020
edited by LuckyDucky  May 1, 2020
 #5
avatar+928 
0

-1 choose 1 is impossible, it is not -1.

HELPMEEEEEEEEEEEEE  May 1, 2020
 #7
avatar+189 
+1

so undefinded? 

SoggyPerson  May 1, 2020
 #10
avatar+928 
0

Yeah, its undefined.

HELPMEEEEEEEEEEEEE  May 1, 2020
 #4
avatar+928 
+1

Anything choose 0 is 1, Anything choose 1 is the number i.e. 1 choose 1 is 1, 2 choose 1 is 2, 3 choose 1 is 3 and so on. You can't use negative numbers is combinatorics.

 May 1, 2020
 #6
avatar+656 
0

Thanks for adding to my growing knowledge of new math!

LuckyDucky  May 1, 2020
 #8
avatar+111360 
+2

Here's proof of LuckyDucky's answer  of 0 choose 0

 

C(0,0)  =

 

      0!                    1                1

__________  =   _____   =  _____   =  1

(0 - 0)! * 0!           0! * 0!        1  * 1

 

But....think about this...we have no objects and we want to choose none of them

 

There's only one way to do this.....forget about it   !!!!

 

 

cool cool cool

 May 1, 2020
 #9
avatar+656 
+1

Wow, that reasoning blows my mind (JK) its very well said!

 

Now I have logic to back up my answer.


:D

LuckyDucky  May 1, 2020

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