import std.conv;
import std.math;
import std.numeric;
import std.stdio;
import std.string;


real solveEquation(int a, int b, real t) {
	//auto g = (T n) => a * n.log + b * n.log.log - t.log;
	auto g = (real n) => pow(n, a) * pow(n.log, b) - t;
	real root;
	if (b > 0) {
		root = findRoot(g, 1.0L, real.max);
	} else {
		root = findRoot(g, 0.0L, real.max);
	}
	return root;
}


void main(){
	auto m = readln.chomp.to!int;
	foreach (i; 0..m) {
		auto s = readln.split;
		auto a = s[0].to!int;
		auto b = s[1].to!int;
		auto t = s[2].to!real;
		auto res = solveEquation(a, b, t);
		writefln("%.10f\n", res);
	}
}