A woman came home and found this letter from her husband:

My Dear Wife,
You will surely understand that I have certain needs that you with Your 54-year-old body can no longer supply. However, I am very happy with you and I value you as a good wife.

Therefore, after reading this letter, I hope that you will not wrongly interpret the fact I will be spending the evening with my 18-year-old secretary at the Comfort Inn Hotel. Please don't be disturbed, I shall be back home before midnight.

When the man came home, he found the following letter on the Dining room table:

My Dear Husband,

I received your letter and thank you for your honesty. I would like to take this opportunity to remind you that you are also 54 years old. At the same time, I would like to inform you that while you are reading this, I will be at the Ritz Carlton with Michael, my tennis coach, who, like your secretary, also is 18!

As a successful businessman and with your excellent knowledge of math, you will understand that we are in the same situation, although with one small difference: 18 goes into 54 a lot more times than 54 goes into 18. Therefore, I will not be back until lunchtime tomorrow.