import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int t = Integer.parseInt(br.readLine());
		PrintWriter pw = new PrintWriter(System.out);
		for (int z = 0; z < t; z++) {
			String[] sa = br.readLine().split(" ");
			int n = Integer.parseInt(sa[0]);
			int m = Integer.parseInt(sa[1]);
			long k = Long.parseLong(sa[2]);

			long rem = (long) n * m;
			double ans = 1;
			while (k > 0) {
				ans *= (rem - 1.0) / rem;
				k -= m;
				rem -= m;
			}
			pw.println(ans);
		}
		pw.flush();
		br.close();
	}
}