mod = 998244353 def main(): import sys import math input = sys.stdin.readline for _ in range(int(input())): t, m, l = map(float, input().split()) 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 > 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()