A businessman sends an email to his wife.

'My Dear Wife,

You will surely understand that I have certain needs that you with your 54 years can no longer supply. I am very happy with you and I value you as a good wife.

Therefore, after reading this email, I hope you will not wrongly interpret the fact that I will be spending the evening with my 18 year-old secretary at the Comfort Inn Hotel.

Please don't be perturbed. 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 e-mail 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 read this, I will be at the Hotel Fiesta with Michael my tennis coach, who, like your secretary, is also 18 years old.

As a successful businessman with your excellent knowledge of mathematics, 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 before lunchtime tomorrow.'