Due to petrol price increasing and a personal conviction about climate change, Han decides to sell his limited-edition Range Rover SVR Sport and is considering buying a smaller vehicle. Han places an advertisement on his car window on 1 December stating:

'2018 Range Rover SVR excellent condition, one owner $165,000 (price negotiable). Please contact Han on the mobile number displayed.'

Obi (Han's neighbour) notices the advertisement on the same day, decides to contact Han that evening, and arranges to inspect the vehicle. After inspecting the vehicle, Obi states that he will contact Han if he is still interested.

On the morning of 3 December, Edna calls Han's mobile number and meets up with him. After inspecting the vehicle, Edna offers $161,000. Han says, 'how about $163,000?' Edna states that she will need to discuss this with her husband and asks Han for his business card. Han tells her to call back by 5pm on his mobile that very day.

Edna contacts Han on his mobile phone at 7.30pm on the same day (3 December). However, Han's mobile phone has run out of battery power by then and his phone remains switched off for the remainder of the night. As there is no facility to leave a message, Edna tries his work number the following day (4 December). However, Han is at a conference, so she leaves a message on his answering machine, stating that she definitely wants the Range Rover for $163,000. Han does not return to his desk until late afternoon and fails to listen to his messages on his answering machine. Edna, then, tries his mobile phone again in the evening but she is still unable to get through.

Roy, a dedicated car dealer, contacts Han on the morning of 5 December, on his mobile phone, stating that he is interested in the Range Rover, and arranges to meet Han during his lunch break to inspect the vehicle. Roy meets Han, and subsequently, agrees to the price of $165,000 for the Range Rover.

Both Obi and Edna contacts Han on the 6 December demanding the vehicle for the advertised price.

Advise Han.