import java.io.*;
import java.math.*;
import java.util.*;

import static java.util.Arrays.*;

public class _456 {
	private static final int mod = (int)1e9+7;

	final Random random = new Random(0);
	final IOFast io = new IOFast();

	/// MAIN CODE
	public void run() throws IOException {
		int TEST_CASE = Integer.parseInt(new String(io.nextLine()).trim());
//		int TEST_CASE = 1;
		while(TEST_CASE-- != 0) {
			a = io.nextInt();
			b = io.nextInt();
//			a = random.nextInt(10)+1;
//			b = random.nextInt(10)+1;
			double t = io.nextDouble();
//			double t = random.nextDouble() * 10;
//			a = 1;
//			b = 1;
//			double t = 10;
			
//			if (b == 0) {
////				io.out.printf("%.10f\n", Math.pow(t, 1.0/a));
//				print(Math.pow(t, 1.0/a));
//				continue;
//			}
			
//			if (a == 0) {
////				io.out.printf("%.10f\n", Math.exp(Math.pow(t, 1.0/b)));
//				print(Math.exp(Math.pow(t, 1.0/b)));
//				continue;
//			}
			
//			io.out.printf("%.10f\n", solve1(t));
//			io.out.printf("%.10f\n", solve2(t));
			print(solve1(t));
//			print(solve2(t));
//			solve2(t);
		}
	}
	
	void print(double x) {
		if (x < 0) {
			if (true) throw new RuntimeException();
			x = -x;
			io.out.print('-');
		}
		x += 5e-11;
		io.out.print((int)x);
		io.out.print('.');
		for (int i = 0; i < 10; i++) {
			x -= (int)x;
			x *= 10;
			io.out.print((int)x);
		}
		io.out.println();
	}
	
	double solve1(double t) {
		double x = 1;
		for (; ; x *= 2) {
			if (f(x) >= t) break;
		}
		double ans = 0;
//		for (int i = 0; x > 1e-13; i++, x /= 2) {
		for (int i = 0; i < 50; i++, x /= 2) {
			if (f(ans + x) <= t) ans += x;
		}
//		dump(f(ans));
//		io.out.printf("%.10f\n", ans);
		return ans;
	}
	
	double solve2(double t) {
		double x = 2;
		for (int i = 0; i < 23; i++) {
			double lx = Math.log(x);
			double v = pow(x, a - 1) * pow(lx, b - 1);
			double f1 = v * x * lx - t;
			double f2 = v * (a * lx + b);
//			dump(x, f1, f2);
//			double d = Math.abs(f1 / f2);
//			if (Math.min(d, d / x) < 1e-10) break;
			x -= f1 / f2;
		}
		return x;
	}
	
	int a, b;
	double f(double x) {
//		return Math.pow(x, a) * Math.pow(Math.log(x), b);
		return pow(x, a) * pow(Math.log(x), b);
	}
	
	double pow(double x, int a) {
		double y = 1;
		for (int i = 0; i < a; i++) y *= x;
		return y;
	}
//	static double pow(double n, int r) {
//		double res = 1;
//		for(; r != 0; r >>>= 1, n = n * n) {
//			if((r&1) == 1) {
//				res = res * n;
//			}
//		}
//		return res;
//	}
	
	/// TEMPLATE
	static int gcd(int n, int r) { return r == 0 ? n : gcd(r, n%r); }
	static long gcd(long n, long r) { return r == 0 ? n : gcd(r, n%r); }
	
	static <T> void swap(T[] x, int i, int j) { T t = x[i]; x[i] = x[j]; x[j] = t; }
	static void swap(int[] x, int i, int j) { int t = x[i]; x[i] = x[j]; x[j] = t; }

	void printArrayLn(int[] xs) { for(int i = 0; i < xs.length; i++) io.out.print(xs[i] + (i==xs.length-1?"\n":" ")); }
	void printArrayLn(long[] xs) { for(int i = 0; i < xs.length; i++) io.out.print(xs[i] + (i==xs.length-1?"\n":" ")); }
	
	static void dump(Object... o) { System.err.println(Arrays.deepToString(o)); } 
	
	void main() throws IOException {
		//		IOFast.setFileIO("rle-size.in", "rle-size.out");
		try { run(); }
		catch (EndOfFileRuntimeException e) { }
		io.out.flush();
	}
	public static void main(String[] args) throws IOException { new _456().main(); }
	
	static class EndOfFileRuntimeException extends RuntimeException {
		private static final long serialVersionUID = -8565341110209207657L; }

	static
	public class IOFast {
		private InputStream in = System.in;
		private PrintWriter out = new PrintWriter(System.out);

		private static int pos, readLen;
		private static final byte[] buffer = new byte[1024 * 8];
		private static char[] str = new char[500*8*2];
		private static boolean[] isDigit = new boolean[256];
		private static boolean[] isSpace = new boolean[256];
		private static boolean[] isLineSep = new boolean[256];

		static { for(int i = 0; i < 10; i++) { isDigit['0' + i] = true; } isDigit['-'] = true; isSpace[' '] = isSpace['\r'] = isSpace['\n'] = isSpace['\t'] = true; isLineSep['\r'] = isLineSep['\n'] = true; }
		public byte read() throws IOException { if(pos >= readLen) { pos = 0; readLen = in.read(buffer); if(readLen <= 0) { throw new EndOfFileRuntimeException(); } } return buffer[pos++]; }
		public int nextInt() throws IOException {
			byte first = (byte)nextChar();
			boolean minus = false;
			int res = 0;
			if (first == '-') {
				minus = true;
			} else {
				res = first - '0';
			}
			while (true) {
				byte b = read();
				if (isSpace[b]) break;
				res = res * 10 + b - '0';
			}
			return minus ? -res : res;
		}
		public long nextLong() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isSpace); int i = 0; long ret = 0; if(str[0] == '-') { i = 1; } for(; i < len; i++) ret = ret * 10 + str[i] - '0'; if(str[0] == '-') { ret = -ret; } return ret; }
		public char nextChar() throws IOException { while(true) { final int c = read(); if(!isSpace[c]) { return (char)c; } } }
		int reads(int len, boolean[] accept) throws IOException { try { while(true) { final int c = read(); if(accept[c]) { break; } if(str.length == len) { char[] rep = new char[str.length * 3 / 2]; System.arraycopy(str, 0, rep, 0, str.length); str = rep; } str[len++] = (char)c; } } catch(EndOfFileRuntimeException e) { ; } return len; }
		int reads(char[] cs, int len, boolean[] accept) throws IOException { try { while(true) { final int c = read(); if(accept[c]) { break; } cs[len++] = (char)c; } } catch(EndOfFileRuntimeException e) { ; } return len; }
		public char[] nextLine() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isLineSep); try { if(str[len-1] == '\r') { len--; read(); } } catch(EndOfFileRuntimeException e) { ; } return Arrays.copyOf(str, len); }
		public String nextString() throws IOException { return new String(next()); }
		public char[] next() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isSpace); return Arrays.copyOf(str, len); }
//		public int next(char[] cs) throws IOException { int len = 0; cs[len++] = nextChar(); len = reads(cs, len, isSpace); return len; }
		public double nextDouble() throws IOException { return Double.parseDouble(nextString()); }
//		public double nextDouble() throws IOException {
//			double res = nextChar() - '0';
//			while (true) {
//				byte c = read();
//				if (c == '.') break;
//				res = res * 10 + c - '0';
//			}
//			double d = 1;
//			while (true) {
//				byte c = read();
////				dump(c);
//				if (!isDigit[c]) break;
//				res = res * 10 + c - '0';
//				d *= 10;
//			}
////			dump(1);
//			return res / d;
//		}
		public long[] nextLongArray(final int n) throws IOException { final long[] res = new long[n]; for(int i = 0; i < n; i++) { res[i] = nextLong(); } return res; }
		public int[] nextIntArray(final int n) throws IOException { final int[] res = new int[n]; for(int i = 0; i < n; i++) { res[i] = nextInt(); } return res; }
		public int[][] nextIntArray2D(final int n, final int k) throws IOException { final int[][] res = new int[n][]; for(int i = 0; i < n; i++) { res[i] = nextIntArray(k); } return res; }
		public int[][] nextIntArray2DWithIndex(final int n, final int k) throws IOException { final int[][] res = new int[n][k+1]; for(int i = 0; i < n; i++) { for(int j = 0; j < k; j++) { res[i][j] = nextInt(); } res[i][k] = i; } return res; }
		public double[] nextDoubleArray(final int n) throws IOException { final double[] res = new double[n]; for(int i = 0; i < n; i++) { res[i] = nextDouble(); } return res; }
	}
}