1. John started a roof fixing business and sent emails to his neighbors offering to fix their roofs for a 20% discount. David received the email and read it but didn't respond. Has a contract been formed between John and David? Why or why not?

2. When fixing David's roof, John fell off the ladder and was very injured and very unconscious. David called an ambulance and John was taken to the hospital where he was admitted and treated. When John woke up and was being discharged, the hospital gave him a bill to pay. John said he didn't have to pay the bill. Does John have to pay the bill? Why or Why not?

3. Also, what differences, if any, exist between the interaction between John and David, and John and the hospital?