N, M = map(int, input().split())
problem = [list(map(int, input().split())) for _ in range(N)]

A, B, P = map(list, zip(*problem))

dp = [[0]*(M+1) for _ in range(1<<N)]
for bit in reversed(range(1<<N)):
    for i in reversed(range(M+1)):
        for j in range(N):
            if 1<<j & bit: continue
            dp[bit][i] = max(dp[bit][i], dp[bit|1<<j][i]+(1/A[j]))
            if i < M:
                dp[bit][i] = max(dp[bit][i], dp[bit][i+1]*((P[j]-1)/P[j])+(dp[bit|1<<j][i]+(1/B[j]))*(1/P[j]))

print(dp[0][0])