(a) At Tiffany's sixteenth birthday party, her uncle became aware that she had

recently taken up smoking. Worried about the effect that smoking might have on

Tiffany's health, her uncle promised to pay her HK$ 100,000 if she did not smoke

for one year. A year has elapsed since Tiffany's uncle made the promise and since

Tiffany last smoked. Can Tiffany enforce this promise?

(b) Daniel's father promises to send him to Los Angeles for a month long, all

expenses paid holiday, and puts his promise in writing. Can Daniel enforce his

father's promise?