n = int(input())
eps = pow(10,-12)
for _ in range(n):
    t,mu,l = map(float,input().split())
    right = 5100.0
    left = 0.0
    while abs(right - left) > eps:
        mid = (right+left)/2
        now = (1/3.6*mid*t + 1/3.6/3.6*mid*mid/20/mu)
        if now >= l:
            right = mid
        else:
            left = mid
    moji = str(right)
    if 0 <= right < 10.0:
        print(moji[:4])
    elif 10.0 <= right < 100.0:
        print(moji[:5])
    elif 100.0 <= right < 1000.0:
        print(moji[:6])
    else:
        print(moji[:7])