1. 

package contestVolumes.volume113;

import java.util.Scanner;

/**
 * FWP, Ausgewählte Probleme aus dem ACM Programming Contest, SS10 
 * Problem: 11346 - Probability
 * Link: http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=25&page=show_problem&problem=2321
 * 
 * @author Siegfried Ippisch
 * @version 1.0
 * 
 * Method : Integration
 * Status : Accepted
 * Runtime: 0.252
 */
public class Probability {
	
	public static void main(String[] args){
		Scanner in = new Scanner(System.in);
		
		int n = in.nextInt();
		while(n-- > 0){
			System.out.printf("%.6f%%%n",probability(in.nextDouble(),in.nextDouble(),in.nextDouble()));
		}
		
		in.close();
	}

	private static double probability(double a, double b, double s) {
		if(s == 0)
			return 100;
		double all = a*b;
		if(s > all)
			return 0;
		double x0 = s/b;
		double greater = s*(Math.log(x0/a)) + b*(a-x0);
		return 100*greater/all;
	}
	
}

2.

package acm_11346_probability;

/**
 * FWP, AusgewŠhlte Probleme aus dem ACM Programming Contest, SS10 
 * Problem: acm_11346_probability
 * Link: http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=25&page=show_problem&problem=2321
 * 
 * @author Martin Lambeck
 * @version 1.0, 10.08.2010
 * 
 * Method : stochastik
 * Status : Accepted
 * Runtime: 0.208
 */

import java.util.Scanner;

public class Main
{
	static Scanner sc = new Scanner(System.in);
	
	public static void main(String... args)
	{
		int cases = sc.nextInt();
		
		for (int i = 0; i < cases; i++)
			System.out.printf("%.6f%%%n", testcase());
	}
	
	public static double testcase()
	{
		double a,b,s;
		double p;
		
		a = sc.nextDouble();
		b = sc.nextDouble();
		s = sc.nextDouble();
		
		if (a*b <= s)
			return 0.0;
		if (s == 0)
			return 100.0;
		
		//zero = s/b
		//area = º (b-s/x) FOR x = [zero; a]
		// => area = [x * b - s ln(x)] FOR x1 = zero, x2 = a
		// => area = (a*b - s*ln(x)) - (zero*b - s*ln(x)) = ...
		// p = 1 - area / totalarea = area / (a*b) = ... =  1 + (s * (ln(s / (a*b)) - 1) / (a*b)
		
		p = 1.0 + (s * (Math.log(s / (a * b)) - 1.0)) / (a*b);
		
		p *= 100.0;
		
		return p;		
	}
}

3.

/**
 * ACM Training 2009 
 * ACM Problem #11346 - Probability
 * Link: http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=25&page=show_problem&problem=2321
 * 
 * @author Felix Dietrich
 * @version 1.0, 12/03/2009
 * 
 * Methode: 
 * Status : Accepted
 * Runtime: 0.212
 */

import java.util.Scanner;

class Main
{
	public static void main(String... s)
	{
		Scanner sc = new Scanner(System.in);
		int testcases = sc.nextInt();
		double a, b, S;
		double x0;

		for (int i = 0; i < testcases; i++)
		{
			a = sc.nextDouble();
			b = sc.nextDouble();
			S = sc.nextDouble();

			x0 = S/b;

			if (a*b <= S)
				System.out.println(String.format("%.06f", 0.0) + "%");
			else if (Math.abs(S) < 1e-6)
				System.out.println(String.format("%.06f", 100.0) + "%");
			else
				System.out.println(String.format("%.06f", 100*(a*b-x0*b-S*Math.log(a/x0)) / (a*b)) + "%");
		}
	}
}


4.

/**
 * ACM Training, WS09/10
 * ACM Problem #11346 Probability
 * Link: http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=25&page=show_problem&problem=2321
 * 
 * @author Doina Logofatu
 * @version 1.0, 12/03/2009
 * 
 * Methode: Math, Probability
 * Status : Accepted
 * Runtime: 0.008
 */

#include <stdio.h>
#include <math.h>

int main(){

  int n;
  double a, b, S;
  double x0, P;

  scanf("%d", &n);

  while(n--){
    scanf("%lf%lf%lf", &a, &b, &S);
    x0 = S/b;

    if(a*b<=S) P = 0;
    else 
    if(S>0) P = ((a-x0)*b-S*log(a/x0))/(a*b)*100;
    else P=100.;
    printf("%.6lf%%\n", P);    
  }
  return 0;

}