The mathematician: "We came past a gas station a few minutes ago. Someone should go back and ask for help." The engineer: "I should have a look at the engine. Perhaps, I can fix it."

The computer scientist: "

"Isn't it disgusting", the first one complains, "how little the general public knows about mathematics?" "Well", his colleague replies, "you're perhaps a bit too pessimistic." "I don't think so", the first one replies. "And anyhow, I have to go to the washroom now." He goes off, and the other professor decides to use this opportunity to play a prank on his colleague.

He makes a sign to the pretty, blonde waitress to come over. "When my friend comes back, I'll wave you over to our table, and I'll ask you a question. I would like you to answer: x to the third over three. Can you do that?"

"Sure." The girl giggles and repeats several times: "x to the third over three, x to the third over three, x to the third over three..." When the first professor comes back from the washroom, his colleague says: "I still think, you're way too pessimistic. I'm sure the waitress knows a lot more about mathematics than you imagine."

He makes her come over and asks her: "Can you tell us what the integral of x squared is?" She replies: "x to the third over three." The other professor's mouth drops wide open, and his colleague grins smugly when the waitress adds: "...

The mathematician: "Three is a prime, five is a prime, seven is a prime, but nine is not a prime. Therefore, the hypothesis is false." The physicist: "Three is a prime, five is a prime, seven is a prime, nine is not a prime, eleven is a prime, and thirteen is a prime. Hence, five out of six experiments support the hypothesis. It must be true."

The engineer: "Three is a prime, five's a prime, seven's a prime, nine's a prime..."

"Get out of my way - or I'll differentiate you till you're zero!"

"Try it - I'm ex..."

Same alley, same function, but a different operator:

"Get out of my way - or I'll differentiate you till you're zero!"

"Try it - I'm ex..." "Too bad... I'm d/dy."

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.

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!"

Proof. No cat has eight tails. Since one cat has one more tail than no cat, it must have nine tails.

Student: 3000!

"You take two thirds of water, one third of cream, one third of broth..."

The apprentice: "But that makes four thirds already!"

"Well - just take a larger pot!"