Answer:
There is no contract since Patty's acceptance was never received by Vance.
Step-by-step explanation:
Without an acceptance, there is no contract. There is even a postal acceptance rule that states that the date of the acceptance is the same date as the mail was sent. This is prevent any issues due to late mail, for example if the mail had arrived April 5th instead of 1st, the acceptance would be valid because it was mailed before April 1st. The problem here is that the acceptance never arrived, therefore it is not valid, so there is no contract.