#include <bits/stdc++.h>
#include <atcoder/segtree.hpp>
using namespace std;

using i32 = int;
using i64 = long long;
using i128 = __int128_t;
using f64 = double;
using p2 = pair<i64, i64>;
using p3 = tuple<i64, i64, i64>;

void _main();
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(18);
  _main();
}

f64 op(f64 a, f64 b) {return a * b;}
f64 e() {return 1;}
void _main() {
  i64 tt;
  cin >> tt;
  atcoder::segtree<f64, op, e> seg(200000);
  for (i64 i = 1; i < 200000; i++) {
    seg.set(i, f64(i - 1) / i);
  }
  for (;tt--;) {
    i64 n, m, k;
    cin >> n >> m >> k;
    if (k <= (n - 1) * m) {
      f64 ans = 1;
      i64 c = (k + m - 1) / m;
      ans = seg.prod(n - c + 1, n + 1);
      ans += (1 - ans) * (m - 1) / m;
      cout << ans << "\n";
    } else {
      f64 ans = 1;
      ans = seg.prod(m - (k % m) + 1, m + 1);
      cout << ans << "\n";
    }
  }
}