Final answer:
In Petterson v. Pattberg, the court ruled that Pattberg could revoke his offer to reduce the mortgage amount before Petterson completed the act of payment, as the offer could be withdrawn anytime before actual performance.
Step-by-step explanation:
The case of Petterson v. Pattberg pertains to the area of contract law, specifically involving an offer and the revocation of that offer. In this case, Pattberg offered to deduct a certain amount from a mortgage if Petterson paid off the mortgage early.
The court ultimately ruled that Pattberg could revoke the offer before Petterson had completed the act of payment because preparing to perform was not enough; performance had to be completed to create the contract based on the offer. This case illustrates the legal principle that until there is performance, an offer can generally be withdrawn.