import strutils, sequtils, math, strscans

proc printf(formatstr: cstring) {.header: "<stdio.h>", importc: "printf", varargs.}

# proc f(n, a, b : float64): float64 = pow(n, a) * pow(ln(n), b)
proc f(n, a, b : float64): float64 = a*ln(n) + b*ln(ln(n))

when isMainModule:
  var
    m: int
    input = stdin.readLine
  discard input.scanf("$i", m)
  for i in 0..m-1:
    var a, b, t: float64
    input = stdin.readLine
    discard input.scanf("$f $f $f", a, b, t)
    var
      (l, r) = (0.0, 1000000000.0)

    for i in 1..64:
      var mid = (l + r) / 2
      if f(mid, a, b) <= ln(t): l = mid
      else: r = mid

    printf("%.11f\n", r)