def business_rule_3(amount: int, account: int, use_br: bool, threshold: int) -> bool:
    """
    Account sends transactions with combined total value >= threshold within a day. Only works for scatter-gather.

    :param amount: transaction value
    :param account: number of involved accounts
    :param use_br: whether to use this br
    :param threshold: the threshold
    :return: True when the laundering was successful, false when it is caught
    """
    if not use_br:
        return True

    if amount * (account - 2) < threshold:
        return True
    else:
        return False