An infinite crowd of mathematicians enters a bar. The first one orders a pint, the second one a half pint, the third one a quarter pint... "I understand", says the bartender - and pours two pints.

Q: When did Bourbaki stop writing books? A: When they realized that Serge Lang was a single person...

Teacher: What is 2k + k? Student: 3000!

Q: What do you get if you divide the cirucmference of a jack-o-lantern by its diameter? A: Pumpkin Pi!

Q: Why do you rarely find mathematicians spending time at the beach? A: Because they have sine and cosine to get a tan and don't need the sun!

Q: Why do mathematicians, after a dinner at a Chinese restaurant, always insist on taking the leftovers home? A: Because they know the Chinese remainder theorem!

Teacher: "Who can tell me what 7 times 6 is?" Student: "It's 42!" Teacher: "Very good! - And who can tell me what 6 times 7 is?" Same student: "It's 24!"

A mathematician is flying non-stop from Edmonton to Frankfurt with AirTransat. The scheduled flying time is nine hours. Some time after taking off, the pilot announces that one engine had to be turned off due to mechanical failure: "Don't worry - we're safe. The only noticeable effect this will have for us is that our total flying time will be ten hours instead of nine." A few hours into the flight, the pilot informs the passengers that another engine had to be turned off due to mechanical failure: "But don't worry - we're still safe. Only our flying time will go up to twelve hours." Some time later, a third engine fails and has to be turned off. But the pilot reassures the passengers: "Don't worry - even with one engine, we're still perfectly safe. It just means that it will take sixteen hours total for this plane to arrive in Frankfurt." The mathematician remarks to his fellow passengers: "If the last engine breaks down, too, then we'll be in the air for twenty-four hours altogether!"