Kate, a recent law school graduate sent a letter to Jenny, her classmate on Friday 1 July 2022 and told her that she is moving to take a new job in another country and asked Jenny whether she wanted "the stuff at my flat for $15,000. Jenny received the letter on Saturday 2 July 2022, and on Monday 4 July 2022, Jenny sent Kate a letter accepting the offer. The next day, Jenny changed her mind, called Kate and told her to forget the deal. Since Jenny said she is not interested, Kate then sold the stuff to Ally for $13,000. Later that week, Kate received the letter that Jenny had sent Monday 4 July 2022. Is there a contract between Kate and Jenny? Why?