Contract Law Assignment: Dana And Lana

Answer the following hypotheticals providing as much information as possible.  
1. Dana owns a bakery and wants to purchase a delivery truck from Lana.  She calls Lana and offers Lana $20,000 for the truck.  Lana responds in an email, “How about $22,000?”  Dana writes back, “Never mind, no thank you, I can do better.”  The next day, Lana changes her mind and calls Dana and says, “Ok, we can do the deal for $20,000.  I will sell you the truck for $20,000.” Explain whether Dana and Lana have formed an enforceable contract, using the law of offer and acceptance. 
2. Danny is a 16 year old boy.  He is interested in buying a new bike and has saved $200.  He goes to Big Bob’s Bike Shop and purchases a new bike for $190.  Later that day Danny changed his mind, thinking he should have put the money toward a new Xbox.  He brings the bike back to Big Bob’s and asks to void the contract.a. What was the consideration in the contract to buy the bike? b. Explain whether Big Bob must take the bike back from Danny.c. Explain whether this is a contract that would need to be in writing to be enforceable?  
3. Ellie is selling her used car, a Toyota Corolla for $2,000.  It has 87,000 miles on it.  Last year, Ellie got into a minor car accident, and replaced the whole bumper.  It looks good as new.  Cal makes an offer of $2,000, and asks Ellie, “Has this car ever been in an accident.  It’s really important to me that the car is in good shape.”  Ellie considers the question and responds, “No, no accident, the car is in perfect working order.”  Cal buys the car for the full price.  The following month, the bumper comes loose and falls off.  If Ellie sues Cal, what do you think the result will be?  Rely on specific contract law principles to explain your response. 
4. Lizzie is planning her wedding and heard that Dave’s DJ is the best in town.  She contacts Dave by phone, and asks if he is available on the date, December 31, 2019.  Dave tells her the date is open and he will pencil her name in.  Let’s assume on January 1, 2019, Dave calls Lizzie for details about her wedding and she says, Oh, sorry, I found another band to play!  I don’t need you anymore.”  Can Dave enforce the promise in court?