from sys import stdin
input = stdin.readline

for _ in range(int(input())):
    N, M, K = map(int, input().split())

    ans = 1
    now = 1
    for i in range(N):
        if K <= M*i:
            break
        ans -= now/(N-i)/M
        now *= (N-i-1)/(N-i)
    now = 1
    for i in range(M-1):
        if K <= M*(N-1)+1+i:
            break
        ans -= now/(M-1-i)*(M-1)/M
        now *= (M-i-2)/(M-1-i)

    print(ans)