using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
using System.Security.Cryptography;

class Program
{
    static int NN => int.Parse(ReadLine());
    static long[] NList => ReadLine().Split().Select(long.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var t = NN;
        var ans = new double[t];
        for (var u = 0; u < t; ++u)
        {
            var c = NList;
            var (n, m, k) = (c[0], c[1], c[2]);
            var d = (k + m - 1) / m;
            if (k <= (n - 1) * m)
            {
                ans[u] = 1 - (double)d / n / m;
            }
            else
            {
                ans[u] = 1 - (double)(k % m) / m;
            }
        }
        WriteLine(string.Join("\n", ans));
    }
}