2. (a) Sarah, a manufacturer of paper products such as paper towels and napkins, wrote to Tom, a buyer for Goodfood, a local supermarket chain in New York City: "September 1, I offer to sell you 30 boxes of 20 rolls of paper towels each, price $0.99 per roll or $594 total.This is a firm offer until October 20 [Signed] Sarah."The letter was received on September 2. On September 10, Tom received a letter from Sarah: "I hereby revoke my offer of September 1." On October 17, Tom wrote to Sarah: "I hereby accept your offer of September 1."The letter was mailed on October 17 by authorized means. The letter was received on October 22. Was a contract formed?Explain.

(b) Instead of the facts stated in (a) above, assume that Sarah's offer stated that it was a firm offer for four months, and that on December 14, Tom received a letter from Sarah, dated December 12, which stated:"I hereby revoke my offer of September 1."On December 15, Tom mailed an acceptance.Is there a contract?Explain.

(40 points)