mistake {Ans: a belief that is not in accord with the facts}coming of age rule {Ans: in common law, the view that a persons legal birthday is 12:01 a.m. of the day before his or her actual birthday}unjust enrichment {Ans: something for nothing}termination by lapse of time {Ans: when an opportunity to form a contract ends because the offeree fails to accept an offer within the time specified}offer {Ans: a proposal made by one party (the offeror) to another person (the offeree) that indicates a willingness to enter into a contract}A contract my be either? {Ans: oral or written express or implied formal or simple entire or divisible}