import math


n = int(input())
for _ in range(n):
    t,mu,l = map(float,input().split())
    ans = 3.6 * math.sqrt( (10*mu*t)**2 + 20*mu*l) - 36 * mu * t
    moji = str(ans) + "0" * 10
    if 0 <= ans < 10.0:
        print(moji[:4])
    elif 10.0 <= ans < 100.0:
        print(moji[:5])
    elif 100.0 <= ans < 1000.0:
        print(moji[:6])
    else:
        print(moji[:7])