#include <bits/stdc++.h>
#include <atcoder/all>

using namespace std;
using namespace atcoder;

using ll = long long;
using mint = modint998244353;
// using mint = modint1000000007;

template <typename T> using vec = vector<T>;
template <typename T> using pa = pair<T, T>;
template <typename T> using mipq = priority_queue<T, vec<T>, greater<T>>;

#define REP(_1, _2, _3, _4, name, ...) name
#define REP1(i, n) for (auto i = decay_t<decltype(n)>{}; (i) < (n); ++(i))
#define REP2(i, l, r) for (auto i = (l); (i) < (r); ++(i))
#define REP3(i, l, r, d) for (auto i = (l); (i) < (r); i += (d))
#define rep(...) REP(__VA_ARGS__, REP3, REP2, REP1)(__VA_ARGS__)
#define rrep(i, r, l) for (int i = (r); i >= (l); --i)
template <typename T> bool chmax(T &a, const T &b) { return (a < b ? a = b, true : false); }
template <typename T> bool chmin(T &a, const T &b) { return (a > b ? a = b, true : false); }

constexpr int INF = 1 << 30;
constexpr ll LINF = 1LL << 60;
constexpr int mov[4][2] = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};

void solve();

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(15);
    int T = 1;
    cin >> T;
    while (T--) solve();
}

// 1個食べて、
// - okだったらぜんぶ食べて次へ
// - ngと同じだったら他ぜんぶ食べれる
// - ngだったら死

void solve() {
    int N, M, K;
    cin >> N >> M >> K;

    auto calc = [&] (this auto self, int n, int k) -> double {
        if (k <= 0) return 1;
        if (n == 0) return 0;
        double res = 0;
        res += (double)(n - 1) / n * self(n - 1, k - M);
        res += (double)1 / n * (M - 1) / M;
        return res;
    };

    cout << calc(N, K) << '\n';
}