def k_value(rela_count, answer_count, question_count):
    """
        k = count(Q&A) / (count(Q) * count(A))

    :param rela_count:
    :param answer_count:
    :param question_count:
    :return:
    """
    if answer_count == 0:
        return 0

    return rela_count / (answer_count * question_count)