#!/usr/bin/env PyPy3

from collections import Counter, defaultdict, deque
import itertools
import re
import math
from functools import reduce
import operator
import bisect
from heapq import *
import functools
from decimal import *
mod=998244353

import sys
input=sys.stdin.readline
n = int(input())
for _ in range(n):
    t,myu,l=map(Decimal,input().split())
    v = -10 * myu * t + (100 * myu ** 2 * t ** 2 + 20 * myu * l) ** Decimal(0.5)
    V = v * Decimal(3.6)
    print('{:.2f}'.format(math.floor(V * 100) / 100))