An infinite number of mathematicians walk into a bar. The first one says, "I'll have a pint of lager please;" the second one says, "I'll have half a pint;" the third one, "A quarter of a pint;" the fourth one, "An eighth of a pint," and so on.
The barman says, "You're all idiots," and pours them two pints.
My favourite beer / maths joke is the following:
An infinite number of mathematicians walk into a bar. The first one says, "I'll have a pint of lager please;" the second one says, "I'll have half a pint;" the third one, "A quarter of a pint;" the fourth one, "An eighth of a pint," and so on.
The barman says, "You're all idiots," and pours them two pints.