## https://yukicoder.me/problems/no/2389


def main():
    N, M = map(int, input().split())
    abp = []
    for _ in range(N):
        a, b, p = map(int, input().split())
        abp.append((a, b, p))
    
    exp = [[0] * (2 ** N) for _ in range(M + 2)]
    for m in reversed(range(M + 1)):
        for bit in reversed(range(2 ** N)):

            for i in range(N):
                if (1 << i) & bit == 0:
                    a, b, p = abp[i]
                    new_bit = bit | (1 << i)

                    # ちゃんと解く
                    x1 = (1 / a) + exp[m][new_bit]

                    # 乱択で解く
                    x2 = 0
                    if m < M:
                        x2 = (((1 / b) + exp[m][new_bit]) / p) + ((p - 1) * exp[m + 1][bit] / p)

                    exp[m][bit] = max(x1, x2, exp[m][bit])
    print(exp[0][0])




if __name__ == '__main__':
    main()