# C Program to Find NCR Factorial of a Number

How to Write C Program to Find NCR Factorial of a Number with an example. The mathematical formula behind this NCR factor is nC = n! / (r! (n-r)!)

## C Program to Find NCR Factorial of a Number

This program allows the user to enter two positive integers. And then, it will calculate the NCR Factorial of the given number

```/* C Program to Find NCR Factorial of a Number */
#include <stdio.h>

int Cal_Fact(int);

int main()
{
int n, r, ncr;

printf("\n Please Enter the Values for N and R: \n");
scanf("%d %d", &n, &r);

ncr = Cal_Fact(n) / (Cal_Fact(r) * Cal_Fact(n-r));
printf("\n NCR Factorial of %d and %d = %d", n, r, ncr);

return 0;
}

int Cal_Fact(int Number)
{
int i;
int Factorial = 1;

for (i = 1; i <= Number; i++)
{
Factorial = Factorial * i;
}
return Factorial;
}```

From the above program to Find NCR Factorial of a Number code snippet, we used a function called Cal_Fact to calculate the factorial of a number. Next, we are calling that function to calculate the factorial of n, r, and n-r. I suggest you to refer Factorial of Number article in C Programming to understand the factorial program

`nCr  = 6! / (2! (6-2)!)  = 720/ (2 * 24) =  15`