import std.algorithm, std.conv, std.range, std.stdio, std.string;
import std.math;      // math functions
import std.typecons;  // Tuple, Nullable, BigFlags

void main()
{
  auto m = readln.chomp.to!int;
  foreach (_; 0..m) {
    auto rd = readln.splitter;
    auto a = rd.front.to!int; rd.popFront();
    auto b = rd.front.to!int; rd.popFront();
    auto t = rd.front.to!real;

    auto calc(real n)
    {
      return n ^^ a * log(n) ^^ b - t;
    }

    auto mi = 0.1L, ma = mi;
    while (calc(ma) < 0) ma *= 2;

    auto bsearch = iota(mi, ma, 1.0e-10L).map!(n => tuple(n, calc(n))).assumeSorted!"a[1] < b[1]";
    writefln("%.10f", bsearch.lowerBound(tuple(0, 0)).back[0]);
  }
}