from math import isqrt
for _ in range(int(input())):
    tf, mf, lf = map(float, input().split())
    t = int(tf * 100 + 0.5)
    m = int(mf * 100 + 0.5)
    l = int(lf * 100 + 0.5)
    r2 = 36 * 36 * ((10 * m * t) ** 2 + 20 * 10000 * m * l)
    r = isqrt(r2)
    ans = r - 360 * m * t
    ans //= 1000
    print(f'{ans // 100}.{ans % 100:02d}')
    # vt+v^2/20m=l
    # v^2 +20mt v -20ml=0
    # v=-10mt + sqrt((10mt)^2+20ml) = 20ml / (10mt + sqrt((10mt)^2+20ml))