import math
T = int(input())
for _ in range(T):
	tf,muf,lf = input().split()
	t = int(tf.replace(".", ""))
	mu = int(muf.replace(".", ""))
	l = int(lf.replace(".", ""))
	#print(t,mu,l)
	targ = int((-10*mu*t+math.sqrt(100*mu*mu*t*t+20*10000*mu*l))*36/1000)
	print(f"{targ/100:.2f}")