On May 12, Leonard offered to sell Ginrich, an acquaintance, a used washer- dryer for $ 400. Leonard told Ginrich that he had until May 17 to accept this offer. On May 13, Leonard received an offer to purchase the washer- dryer for $ 450 from Bolton, a friend. Leonard immediately accepted Bolton’s offer. On May 14, Bolton saw Ginrich and mentioned that he ( Bolton) had just purchased a washer- dryer from Leonard. On May 15, however, Ginrich notified Leonard that he accepted the offer to buy the washer- dryer for $ 400. Was Ginrich’s acceptance valid?