def _get_discount_offer(basket, balance, item, num_items_offer, price_offer):
    """
    Update the balance and the basket for a DISCOUNT item offer
    """
    if item in basket:
        offers_sold = basket[item]//num_items_offer
        num_items_to_remove = offers_sold * num_items_offer
        balance += offers_sold * price_offer
        basket[item] -= num_items_to_remove

    return basket, balance