9C4: 9 choose 4 work with steps provide the detailed information about what is the total number of possible combinations occur (nCk) while choosing 4 elements at a time from 8 distinct elements without considering the order of elements.
nCk of 9C4:
9 CHOOSE 4 = 126
where,
9 is the total number of distinct elements (n),
4 is the the number of elements drawn or choosen at a time (k),
126 is the total number of possible combination (C).
9C4 Points to Remember:
9C4 is the type of nCr or nCk problem. The below 9 choose 4 work with steps help users to understand the combinations nCk formula, input parameters and how to find how many possible combinations/events occur while drawing 4 elements at a time from 9 distinct elements without considering the order of elements.
Solved Example: :
what is 9 choose 4?
step 1 Address the input parameters and observe what to be found:
Input values:
Total number of distinct elements (n) = 9
The number of elements drawn at a time (k) = 4
What to be found:
Find the total number of possible combinations while choosing 4 elements at a time from 9 distinct elements without considering the order of elements.
step 2 Find the factorial of 9:
9! = 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 x 9
step 3 Find the factorial of 4:
4! = 1 x 2 x 3 x 4
step 4 Find the factorial of difference between 9 and 4:
(9 - 4)! = 5!
5! = 1 x 2 x 3 x 4 x 5
step 5 Apply the values of 9!, 4! and 5! in the nCk formula:
nCk = n!/k! (n - k)!
9C4 =9!/4! x 5!
=1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 x 9/(1 x 2 x 3 x 4) x (1 x 2 x 3 x 4 x 5)
step 6 Simplify the above 9C4 equation:
=1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 x 9/(1 x 2 x 3 x 4) x (1 x 2 x 3 x 4 x 5)
= 6 x 7 x 8 x 9/24
= 3024/24
9C4 = 126
Hence,
9 choose 4 equals to 126