The Head Professor at the Over Ambitious University thinks students do not read enough books from the university's extensive library. On Monday, he announces over Campus Radio that he will donate his brand new shiny superbike to the first student who reads ten self-improvement books from the library before the weekend. On Tuesday, he regrets his rash offer and puts up posters around campus, retracting his offer. On Thursday, over Campus Radio, he announces that the offer is withdrawn. Advise the following students:

a) Lucy, a robust bookworm, who read 10 books by the weekend but was not aware of the offer until she finished reading all of them.

b) Emily, having heard the offer over campus radio on Monday, rushed to the library. Despite being ill on Tuesday, she read 10 books by Wednesday.

c) David was told by another student about the withdrawal of the offer just as he was about to go to the library on Wednesday. He said 'they can't do that' and completed the reading.

d) Anita, having heard of the offer on Monday, was too drunk on Tuesday and Wednesday to go to the campus library but managed to go on Thursday. She was mid-way through reading some books when she heard the withdrawal over the radio.

e) The same scenario as (d) but this time the prize money is 5,000

Please describe up to one thousand five hundred words. Please insert relevant cases with authorities. Thank you.