An engineer, a physicist, and a mathematician are shown a pasture with aherd of sheep, and told to put them inside the smallest possible amount of fence. The engineer is first.

He herds the sheep into a circle and then puts the fence around them, declaring, "A circle will use the least fence for a given area, so this is the best solution." The physicist is next. She creates a circular fence of infinite radius around the sheep, and thendraws the fence tight around the herd, declaring, "This will give the smallest circular fence around the herd." The mathematician is last. After giving the problem a little thought, he puts a small fence round himself and then declares, "I define myself to be on the outside and the sheeps to be on the inside!"

A mathematician, an engineer and a physicist sat around a table discussing the best way to measure the volume of a cow. The mathematician suggested the use of geometry and symettry relationships of the cow, but his idea was rejected for being too time-consuming. The engineer suggested placing the cow in a pool of water and measuring the change in the height of the water, but this idea was considered impractical. "It's easy," said the physicist. "We'll make an assumption that the cow is a small sphere, calculate the volume, and then blow it up to the actual size."

An astronomer, a physicist, and a mathematician were on vacation in Scotland. From a train window, they saw a black sheep in the middle of a field. "How interesting", observed the astronomer, "all Scottish sheep are black." To which the physicist replied "No, no! Some Scottish sheep are black!" The mathematician gazed heavenward, then intoned, "In Scotland, there exists at least one field, containing at least one sheep, at least one side of which is black."

An engineer, a chemist and a mathematician are staying in three adjoining cabins at an old motel. First the engineer's coffee maker sets fire. He smells the smoke, wakes up, unplugs the coffe maker, throws it out the window, and goes back to sleep. Later that night, the chemist smells smoke too. He wakes up and sees that a cigarette butt has set the trash can on fire. He says to himself, "Hmm, How does one put out a fire? One can reduce the temperature of the fuel below the flash point, isolate the burning material from oxygen, or both. This could be accomplished by applying water." So he picks up the trash can, puts it in the shower stall, turns on the water, and when the fire is out, goes back to sleep. The mathematician of course has been watching all this out the window. So later, when he finds that his pipe ashes have set the bedsheet on fire, he is not in the least taken aback. He says: "Aha! A solution exists!" and goes back to sleep.

A mathematician, a biologist and a physicist are sitting in a street cafe watching people going in and coming out of the house on the other side of the street. First they see two people going into the house. Time passes. After awhile, they see three people coming out of the house. The physicist: "The measurement wasn't accurate." The biologist: "They have reproduced." The mathematician: "If now exactly one person enters the house then it will be empty again."

An engineer, a mathematician, and a physicist are each sentenced to die by the guillotine. As the physicist is led to the guillotine, she decides that she'd like to observe the blade as it falls, perhaps to verify v=at, and she requests to be strapped in face up. The executioner agrees (why not? it all pays the same...), and straps her in. As the blade falls, it sticks about two thirds of the way down. Seeing this, the crowd cheers - the physicist must be innocent! So the exectuioner unstraps her and sets her free. The mathematician is next. Being well versed in matters statistical (perhaps she is an actuary), she quickly asks to be placed face up as well - I mean, the odds of it happening again are pretty good, especially if the initial conditions are similar. So the excutioner obliges, and once again, the blade sticks about two thirds of the way down. Again the crowd cheers, and the mathematician is also set free. Finally, the engineer. Not willing to do anything in public that is different from her peers, she, too, requests to be placed face up. As the executioner is strapping her in, she's looking up at the blade and the track in which it slides. As she does so, she notices something. "Do you see that?", she asks. "About one third the way up? If you fixed that there..."

An engineer, a mathematician, and a physicist are testing the theory that all odd numbers are prime.

Physicist: "1 is prime, 3 is prime, 5 is prime, 7 is prime, 9 - must be experimental error, 11 is prime, 13 is prime. That's enough data points; the theory is true."

Mathematician: "1 is prime, 3 is prime, 5 is prime. Using mathematical induction, we can infer that all odd numbers are prime."

Engineer: "1 is prime, 3 is prime, 5 is prime, 7 is prime, 9 is prime, 11 is prime, 13 is prime, 15 is prime, 17 is prime, 19 is prime... Hmmm, theory appears to be true."

An engineer, mathematician, and physicist are each asked to determine the volume of a red metal ball. The mathematician measures the diameter, divides it by two to obtain the radius, and then performs a double intergration. The physicist weighs the ball and then weighs it again when immersed in water. Knowing the density of water and the difference in the two weights, she calculates the displaced volume of water, which is the volume of the ball. The engineer turns to her reference text The Physical Properties of Balls and in the chapter entitled "Metal", finds the table labelled "Red". Searching for a row that the contains the appropriate model number (which is stamped on the ball), she reads across to the column "volume", ignoring those dealing with "coefficient of thermal expansion" and "software rev. level".

Three engineers and three mathematicians are traveling by train to a conference. At the station, the three engineers each buy tickets and watch as the three mathematicians buy only a single ticket.

"How are three people going to travel on only one ticket?" asks an engineer.

"Watch and you'll see," answers a mathematician.

They all board the train. The engineers take their respective seats, but all three mathematicians cram into a restroom and close the door behind them. Shortly after the train has departed, the conductor comes around collecting tickets. He knocks on the restroom door and says, "Ticket, please." The door opens just a crack and a single arm emerges with a ticket in hand. The conductor takes it and moves on.

The engineers see this and agree it is quite a clever idea. So after the conference, the engineers decide to copy the mathematicianss on the return trip and save some money (being clever with money, and all that). When they get to the station, they buy a single ticket for the return trip. To their astonishment, the mathematicians don't buy a ticket at all.

"How are you going to travel without a ticket?" asks one perplexed engineer.

"Watch and you'll see," answers a mathematician.

When they board the train, the three engineers cram into one restroom and the three mathematicians cram into another one nearby. The train departs. Shortly afterward, one of the mathematicians leaves his restroom and walks over to the restroom where the engineers are hiding. He knocks on the door and says, "Ticket, please."

Two physicists were riding in a hot air balloon and were blown off course sailing over a mountain trail. They were completely lost, when they spotted a jogger running on the trail and shouted "Can you tell us where we are?" After a few minutes, the jogger yelled back, "You're up in a balloon." One physicist turned to the other, "Just our luck to run into a mathematician". "How did you know he was a mathematician?" "Well, in the first place he took a long time to answer; second, his answer was 100% correct, and third, it was totally useless."

Aleph-null bottles of beer on the wall,
Aleph-null bottles of beer,
You take one down, and pass it around,
Aleph-null bottles of beer on the wall.

Why did the chicken cross the Mobius strip?
To get to the same side.