//25zad
package java_stuff;

import java.util.Scanner;

public class myclass {

	public static void main(String[] args) {
		int n=0,k=0,nf=1,kf=1;
		Scanner scan = new Scanner(System.in);
		System.out.println("Enter K>1.");
		while(k<1)
		k = scan.nextInt();
		System.out.println("Enter N > K.");
		while(n<k)
		n = scan.nextInt();
		for(int j=n;j>=1;j--)
		{
			nf=nf*j;
		}
		for(int j=k;j>=1;j--)
		{
			kf=kf*j;
		}
		System.out.print("N!/K! = " + nf/kf);
	}

}

//26zad
package java_stuff;

import java.util.Scanner;

public class myclass {

	public static void main(String[] args) {
		int n=0,k=0,nf=1,kf=1;
		Scanner scan = new Scanner(System.in);
		System.out.println("Enter K.");
		while(k<1)
		k = scan.nextInt();
		System.out.println("Enter N.");
		while(n<1)
		n = scan.nextInt();
		for(int j=n;j>=1;j--)
		{
			nf=nf*j;
		}
		for(int j=k;j>=1;j--)
		{
			kf=kf*j;
		}
		int sub = n-k,subf = 1;
		for(int j=sub;j>=1;j--)
		{
			subf=subf*j;
		}
		System.out.print("N! * K! / (N-K)! = " + (nf*kf)/subf);
	}

}
//27zad
package java_stuff;

import java.lang.Math;

public class myclass {

	public static void main(String[] args) {
		double n = 3, nf = 1, c = 0;
		double i = 1,s=1;
		while(c < n)
		{
			for(int j = 1;j<n;j++)
				nf=nf*j;
			s = s + (nf/Math.pow(n, i));
			c++;
		}
		System.out.println("Answer: " + s);
	}

}