(a)Alfred is a first year university student. His mother says 'If you get high distinctions in all your subjects this year I will buy you a new Honda Accord'. Alfred works hard and obtains high distinctions in all subjects. However his mother refuses to buy the car, saying that she thinks it is better if she invests the money on the stock market. Is Alfred's mother legally obliged to fulfil her promise? Would it be different if the promise was in writing? Explain.

(B)David is negotiating with Elisabeth for a Holden she has advertised for sale. Elisabeth advertised the car for $30,000. David inspected the car and offered by telephone to buy it for $28,000. Elisabeth replied that $28,000 was too low but she was prepared to agree to $29,000. David said that this price was too high. Thirty minutes later he phoned Elisabeth saying that he had changed his mind and agreed to pay $29,000. However Elisabeth replied that the price was back to $30,000. Discuss.

(C)Foo offers to sell Georgina her Volvo for $30,000. Georgina accepts by letter, posting it on 19 March. Foo does not reply. On 28 March Georgina telephones Foo who says that she has not received the letter so she is free to sell the car to someone else. Discuss.

(D)Hera offers to sell Imelda her BMW for $30,000. Hera says that Imelda has until 30 March to accept. Imelda decides to buy the car. However before she writes to Hera, Hera telephones Imelda on 25 March saying the deal is off because she is selling the car to George. Discuss.