package main

// fmt package provides the function to print anything
import (
   "fmt"
)
func main() {

   // declaring the variables to store the value of n, r and answer
   var n, r, nFactorial, rFactorial, nminusrFactorial, answer int
   fmt.Println("Program to find the nCr using the for loop.")

   // initializing the value of n 
   n = 10

   // initializing the value of r
   r = 8
   nFactorial = 1

   // finding factorial of n
   for i := 1; i <= n; i++ {
      nFactorial = nFactorial * i
   }
   rFactorial = 1

   // finding factorial of r
   for i := 1; i <= r; i++ {
      rFactorial = rFactorial * i
   }
   nminusrFactorial = 1

   // finding factorial of n - r
   for i := 1; i <= n-r; i++ {
      nminusrFactorial = nminusrFactorial * i
   }

   // finding answer by using the formulae
   answer = nFactorial / (rFactorial * nminusrFactorial)

   // printing the result
   fmt.Println("The value of nCr with n =", n, "and r=", r, "is", answer)
}

Program to find the nCr using the for loop.
The value of nCr with n = 10 and r= 8 is 45

package main

// fmt package provides the function to print anything
import (
   "fmt"
)

// this is a recursive function of return type int

// which is returning the factorial of number

// passed in argument
func factorial(n int) int {
   if n == 1 {
      return 1
   }
   return factorial(n-1) * n
}
func main() {

   // declaring the variables to store the value of n, r and answer
   var n, r, nFactorial, rFactorial, nminusrFactorial, answer int
   fmt.Println("Program to find the nCr using the separate function to find the factorial of n, r and, n-r.")

   // initializing the value of n
   n = 10

   // initializing the value of r
   r = 8

   // finding factorial of n
   nFactorial = factorial(n)

   // finding factorial of r
   rFactorial = factorial(r)

   // finding factorial of n - r 
   nminusrFactorial = factorial(n - r)

   // finding answer by using the formulae
   answer = nFactorial / (rFactorial * nminusrFactorial)

   // printing the result
   fmt.Println("The value of nCr with n =", n, "and r=", r, "is", answer)
} 

Program to find the nCr using the separate function to find the factorial of n, r and, n-r.
The value of nCr with n = 10 and r= 8 is 45