charles and ellen, an unmarried couple, run an ice cream store. the business is not incorporated, and they have filed no formation papers with the state. their business is a

partnership

Explanation:

Since they have not filed formation papers, this must be considered a partnership. If they file formation papers, then it could be a limited liability company. Partnerships are created even if no paperwork at all exists. When not even a partnership agreement exists, the partners will share profits and losses equally and are not allowed to collect a salary. They have to wait until any profits are made to collect any money.