mod = 998244353


def main():
    import sys
    import math
    input = sys.stdin.readline

    for _ in range(int(input())):
        t, m, l = map(float, input().split())
        t = int(t * 100 + 0.5)
        m = int(m * 100 + 0.5)
        l = int(l * 100 + 0.5)
        ok = 0
        ng = 510000 + 1
        mid = (ok + ng) // 2
        while ng - ok > 1:
            #v = mid / 360
            #if v * t + (v ** 2 / (20 * m)) > l:
            if 20 * 360 * m * mid * t + (mid ** 2) * (10 ** 4) > 20 * (360 ** 2) * m * l:
                ng = mid
            else:
                ok = mid
            mid = (ok + ng) // 2
        ans = str(ok).zfill(3)
        ans1, ans2 = ans[:-2], ans[-2:]
        print(ans1 + "." + ans2)


if __name__ == '__main__':
    main()