// Arup Guha
// 2/2/2024
// Solution to COP 4516 Final Individual Contest Problem: Slow Typing

import java.util.*;

public class slow {

	public static void main(String[] args) {
	
		Scanner stdin = new Scanner(System.in);
		int nC = stdin.nextInt();
		
		// Process cases.
		for (int loop=0; loop<nC; loop++) {
			
			// Read rate.
			double rate = stdin.nextDouble();
			
			// Convert to decimal
			double fingers = stdin.nextDouble()/10.0;
			
			// Slow me down!
			rate *= (fingers*fingers);
			
			// Get lines of code.
			int loc = stdin.nextInt();
		
			// Let printf round.
			System.out.printf("%.2f\n", loc/rate);
		}
	}
}