In the case of Charles v. Alex, to determine whether or not Alex was entitled to sell the apartment to another buyer depends very much on whether or not the element of offer and acceptance were present and hence formed a legally binding contract between them.
First of all, we have to decide whether or not the advertisement posted by Alex in Hong Kong Daily was an offer or an invitation to treat. An offer is a definite promise or proposal made by the offeror with the serious intention of being bound by such promise or proposal, if it is accepted by the offeree. And an invitation to treat is the expression of the willingness to receive offers for consideration, a statement short of a definite offer which merely furthers the bargaining process. According to Partridge v Critteden , the newspaper advertisement without sufficient details was held to be an invitation to treat only. Refer to the fact, the advertisement placed by Alex in Hong Kong Daily on 8th September, 2011 did not state the detail information regarding the apartment, e.g. the address, the size, therefore, this advertisement is only an invitation to treat but not amount to an offer.
Assuming all the details regarding the apartment was well communicated between Alex and Charles. The offer was then appeared at the time when Charles called Alex on 9th September, 2011 for offering a purchase at HK$30 Million. A counter offer, offer suggested after the offeree had the intention to reject the offer that he has received, then appeared, offered by Alex, rejected the offer of HK$30 Million purchase by