Chan lives in the countryside and in a house consists of 5 bedrooms. He decided to convert three of his rooms into a guesthouse to let out to holiday makers. Chan contacted Wong and they agreed that Wong would carry out the conversion work for $500,000. They also agreed that the work would be completed by 1 June, in time for the summer holiday season. By the beginning of March it became clear to Chan that Wong was falling behind schedule. Wong admitted that he was finding it difficult to employed skilled labourers. He said he had underestimated the costs and was not likely to finish the work on time. Chan, having already taken holiday bookings for 1 June, offered Wong an extra $10,000 if he completed the work on time. Wong agreed and went on to complete the work by 1 June. When the work was complete Chan paid Wong $500,000 but not the extra $10,000.

Chan's sister, Olivia, is a professional photographer. On the day of the opening of the guesthouse, she decided, of her own initiative, to spend most of the day taking photographs in the opening day. After that day, Chan was so impressed with the photographs that he said he would give Olivia $2,000. However, Chan never paid.

Advise Wong and Olivia respectively as to whether they could enforce Chan's promises of payment.