1. 코드

import java.io.*;
import java.util.*;

public class Solution {
    public static void main(String[] args) throws Exception {
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        int Test = Integer.parseInt(bf.readLine());

        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < Test; i++) {
            String dabf = bf.readLine();
            String[] dabf_arr = dabf.split(" ");

            double D = Double.parseDouble(dabf_arr[0]);
            double A = Double.parseDouble(dabf_arr[1]);
            double B = Double.parseDouble(dabf_arr[2]);
            double F = Double.parseDouble(dabf_arr[3]);

            double time = D/(A+B);

            double F_distance = F * time;

            String answer = String.format("%.10f", F_distance);

            sb.append("#").append(i+1).append(" ").append(answer).append("\n");
        }
        System.out.println(sb.toString().trim());
    }
}