from math import log

q=int(input())

ANS=[-1]*q

for tests in range(q):
    a,b,t=map(float,input().split())

    # n**a * log(n)**b = t

    if a==0:
        ANS[tests]=2.718281828459045**(t**(1/b))
        continue

    if b==0:
        ANS[tests]=t**(1/a)
        continue
        

    MAX = 10
    MIN = 0
    tb = t**(1/b)

    while MAX-MIN>10**(-9):
        mid=(MAX+MIN)/2

        if (mid ** (a/b)) * log(mid)>=tb:
            MAX=mid
        else:
            MIN=mid

    ANS[tests]=(MAX+MIN)/2

print("\n".join(map(str,ANS)))