A professor of mathematics sent a fax to his wife ""Dear Wife, You must realize that you are 54 years old, and I have certain needs that you are no longer able to satisfy. I am otherwise happy with you as a wife and sincerely hope that you will not be hurt or offended to learn that by the time you receive this letter, I will be at the Grand Hotel with my 18-year-old teaching assistant. I'll be home before midnight. Your Husband."" When he arrived at the hotel, there was a faxed letter waiting fo…