Under what circumstances will an apparent invitation to treat situation become an offer? Andrew offered to purchase Rob's house and gave Rob six weeks for a definite answer. Rob, on the basis of this offer, bought another house. Before the six weeks expired, but after Rob had bought the second house, Andrew withdrew his offer. Is Andrew entitled to do this? Could an offer sent by fax be accepted by letter if the offeror had not specified a particular method of acceptance? Give reasons. How can businesses that make offers protect themselves from the risk of loss associated with the rules of offer and acceptance by post