Write a C program

Problem 8: Write a program to calculate the factorial of a given number which is given by. Factorial of a given number n=n! =n*(n-1)*(n-2)*..............*1 Using the above code of finding factorial write a code to calculate the permutation npr with given values n and r (i.e) npr = n! / (n-r)! You have to provide inputs for the values n and r