Peter, a marketing student at WSU, has a Macbook Air which he has advertised on a private sales website, www.lemontree.com.au, for $2000. Bob saw the advertisement and sends an email to Peter and asked, "Is this laptop the latest model and does it have a good camera and quality speakers? I can pay you $1500." Peter replied via email, "Yes it is the Macbook XVIII, the latest premium range and it does have the features you enquired about. I have a lot of interest in the laptop.I am keen to sell quickly.My final price is $1900." Bob replies via email stating, "We've got a deal, but I will need to pay you in weekly instalments." Peter then states, "If I don't hear from you in 3 days' time, I assume that you are keen to purchase the laptop. I will need a lump sum amount to be paid I'm afraid." The next day Bob finds out that Peter sold the laptop to his friend Luke for $1500.00. He approaches Peter and says, "We had a deal, you owe me the laptop". Advise Bob whether there is a contract in existence and if he has any rights under it.

You are advised to discuss the elements of a Contract generically in a separate introductory paragraph (since they relate to all the scenarios below). Then, attempt a mini-IRAC answer for each of the scenarios, elaborating only on the specific relevant rules and principles under each of the elements, as supported by relevant case-law.