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Mathematical Jokes

Maths and Alcohol don't mix, so...


Then there's every parent's scream when their child walks into the room dazed and staggering:


Old Statisticians never die, they just get broken down by age and sex.

Dean, to the physics department. "Why do I always have to give you guys so much money, for laboratories and expensive equipment and stuff. Why couldn't you be like the maths department - all they need is money for pencils, paper and waste-paper baskets. Or even better, like the philosophy department. All they need are pencils and paper."

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A somewhat advanced society has figured how to package basic knowledge in pill form.

A student, needing some learning, goes to the pharmacy and asks what kind of knowledge pills are available. The pharmacist says "Here's a pill for English literature." The student takes the pill and swallows it and has new knowledge about English literature!

"What else do you have?" asks the student.

"Well, I have pills for art history, biology, and world history," replies the pharmacist.

The student asks for these, and swallows them and has new knowledge about those subjects.

Then the student asks, "Do you have a pill for maths?"

The pharmacist says "Wait just a moment", and goes back into the storeroom and brings back a whopper of a pill and plunks it on the counter.

"I have to take that huge pill for maths?" inquires the student.

The pharmacist replied "Well, you know maths always was a little hard to swallow."

"A mathematician is a device for turning coffee into theorems" -- P. Erdos

Three standard Peter Lax jokes (heard in his lectures) :

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"Algebraic symbols are used when you do not know what you are talking about."

Heisenberg might have slept here.

Moebius always does it on the same side.

Statisticians probably do it

Algebraists do it in groups.

(Logicians do it) or [not (logicians do it)].

This poem was written by Jon Saxton (an author of maths textbooks).

((12 + 144 + 20 + (3 * 4^(1/2))) / 7) + (5 * 11) = 9^2 + 0

Or for those who have trouble with the poem:

A Dozen, a Gross and a Score,
plus three times the square root of four,
divided by seven,
plus five times eleven,
equals nine squared and not a bit more.

'Tis a favorite project of mine
A new value of pi to assign.
I would fix it at 3
For it's simpler, you see,
Than 3 point 1 4 1 5 9.

("The Lure of the Limerick" by W.S. Baring-Gould, p.5. Attributed to Harvey L. Carter).

If inside a circle a line
Hits the center and goes spine to spine
And the line's length is "d"
the circumference will be
d times 3.14159

If (1+x) (real close to 1)
Is raised to the power of 1
Over x, you will find
Here's the value defined:

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Here's a limerick I picked up off the net a few years back - looks better on paper.

       |  2            3 x 3.14           3_
       | z dz  x  cos( ----------) = ln (\/e )
       |                  9

Which, of course, translates to:

Integral z-squared dz
from 1 to the square root of 3
times the cosine
of three pi over 9
equals log of the cube root of 'e'.

And it's correct, too.

The Programmers' Cheer --

Shift to the left, shift to the right!
Pop up, push down, byte, byte, byte!

Three men are in a hot-air balloon. Soon, they find themselves lost in a canyon somewhere. One of the three men says, "I've got an idea. We can call for help in this canyon and the echo will carry our voices far."

So he leans over the basket and yells out, "Helllloooooo! Where are we?" (They hear the echo several times.)

15 minutes later, they hear this echoing voice: "Helllloooooo! You're lost!!"

One of the men says, "That must have been a mathematician."

Puzzled, one of the other men asks, "Why do you say that?"

The reply: "For three reasons. (1) he took a long time to answer, (2) he was absolutely correct, and (3) his answer was absolutely useless."

(I'm not sure if the following one is a true story or not)
The great logician Bertrand Russell (or was it A.N. Whitehead?) once claimed that he could prove anything if given that 1+1=1. So one day, some smarty-pants asked him, "Ok. Prove that you're the Pope." He thought for a while and proclaimed, "I am one. The Pope is one. Therefore, the Pope and I are one."

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Lemma: All horses are the same color.

Proof (by induction):

Case n=1: In a set with only one horse, it is obvious that all horses in that set are the same color.
Case n=k: Suppose you have a set of k+1 horses. Pull one of these horses out of the set, so that you have k horses. Suppose that all of these horses are the same color. Now put back the horse that you took out, and pull out a different one. Suppose that all of the k horses now in the set are the same color. Then the set of k+1 horses are all the same color. We have k true => k+1 true; therefore all horses are the same color.

Theorem: All horses have an infinite number of legs.

Proof (by intimidation):

Everyone would agree that all horses have an even number of legs. It is also well-known that horses have forelegs in front and two legs in back. 4 + 2 = 6 legs, which is certainly an odd number of legs for a horse to have! Now the only number that is both even and odd is infinity; therefore all horses have an infinite number of legs.
However, suppose that there is a horse somewhere that does not have an infinite number of legs. Well, that would be a horse of a different color; and by the Lemma, it doesn't exist.

Theorem: a cat has nine tails.


No cat has eight tails. A cat has one tail more than no cat. Therefore, a cat has nine tails.

My geometry teacher was sometimes acute, and sometimes obtuse, but always, he was right.

Q: What's the title of this picture ?

              ..  .. ____ ..  ..
                ||  |    |  ||
                ||  |____|  ||
                || (      ) ||
                ||  \____/  ||
                ||          ||
                ||          ||
                ||          ||
                ||          ||
                ||          ||
                ||          ||
                ||          ||
                ||          ||
                ||          ||
                ||    (\    ||
                ||    ) )   ||
                ||  //||\\  ||

A: Hypotenuse

Q: What quantity is represented by this ?

                 /\         /\         /\
                /  \       /  \       /  \
                /  \       /  \       /  \
               /    \     /    \     /    \
               /    \     /    \     /    \
              /______\   /______\   /______\
                 ||         ||         ||
                 ||         ||         ||

A: 9, tree + tree + tree

Q: A dust storm blows through, now how much do you have ?
A: 99, dirty tree + dirty tree + dirty tree

I saw the following scrawled on a math office blackboard in college: 1 + 1 = 3, for large values of 1

Asked how his pet parrot died, the mathematician answered "Polynomial. Polygon."

Lumberjacks make good musicians because of their natural logarithms.

Pie are not square. Pie are round. Cornbread are square.

"The integral of e to the x is equal to f of the quantity u to the n."

     /  x      n
     | e  = f(u )
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A physics joke:
"Energy equals milk chocolate square"

Russell to Whitehead: "My Godel is killing me!"

A doctor, a lawyer and a mathematician were discussing the relative merits of having a wife or a mistress.

The lawyer says: "For sure a mistress is better. If you have a wife and want a divorce, it causes all sorts of legal problems.

The doctor says: "It's better to have a wife because the sense of security lowers your stress and is good for your health.

The mathematician says: " You're both wrong. It's best to have both so that when the wife thinks you're with the mistress and the mistress thinks you're with your wife --- you can do some mathematics.

Von Neumann and Norbert Wiener were both the subject of many dotty professor stories. Von Neumann supposedly had the habit of simply writing answers to homework assignments on the board (the method of solution being, of course, obvious) when he was asked how to solve problems. One time one of his students tried to get more helpful information by asking if there was another way to solve the problem. Von Neumann looked blank for a moment, thought, and then answered, "Yes".

Wiener was in fact very absent minded. The following story is told about him: When they moved from Cambridge to Newton his wife, knowing that he would be absolutely useless on the move, packed him off to MIT while she directed the move. Since she was certain that he would forget that they had moved and where they had moved to, she wrote down the new address on a piece of paper, and gave it to him. Naturally, in the course of the day, an insight occurred to him. He reached in his pocket, found a piece of paper on which he furiously scribbled some notes, thought it over, decided there was a fallacy in his idea, and threw the piece of paper away. At the end of the day he went home (to the old address in Cambridge, of course). When he got there he realized that they had moved, that he had no idea where they had moved to, and that the piece of paper with the address was long gone. Fortunately inspiration struck. There was a young girl on the street and he conceived the idea of asking her where he had moved to, saying, "Excuse me, perhaps you know me. I'm Norbert Wiener and we've just moved. Would you know where we've moved to?" To which the young girl replied, "Yes daddy, mommy thought you would forget."

The capper to the story is that I asked his daughter (the girl in the story) about the truth of the story, many years later. She said that it wasn't quite true -- that he never forgot who his children were! The rest of it, however, was pretty close to what actually happened...

Old mathematicians never die; they just lose some of their functions.

During a class of calculus my lecturer suddenly checked himself and stared intently at the table in front of him for a while. Then he looked up at us and explained that he thought he had brought six piles of papers with him, but "no matter how he counted" there was only five on the table. Then he became silent for a while again and then told the following story:

"When I was young in Poland I met the great mathematician Waclaw Sierpinski. He was old already then and rather absent-minded. Once he had to move to a new place for some reason. His wife didn't trust him very much, so when they stood down on the street with all their things, she said: "Now, you stand here and watch our ten trunks, while I go and get a taxi."

She left and left him there, eyes somewhat glazed and humming absently. Some minutes later she returned, presumably having called for a taxi. Says Mr. Sierpinski (possibly with a glint in his eye): "I thought you said there were ten trunks, but I've only counted to nine."
"No, they're TEN!" "No, count them: 0, 1, 2, ..."

Two male mathematicians are in a bar.

The first one says to the second that the average person knows very little about basic mathematics.

The second one disagrees, and claims that most people can cope with a reasonable amount of math.

The first mathematician goes off to the washroom, and in his absence the second calls over the waitress.

He tells her that in a few minutes, after his friend has returned, he will call her over and ask her a question. All she has to do is answer one third x cubed.

She repeats `one thir -- dex cue'? He repeats `one third x cubed'.

Her: `one thir dex cuebd'? Yes, that's right, he says. So she agrees, and goes off mumbling to herself, `one thir dex cuebd...'.

The first guy returns and the second proposes a bet to prove his point, that most people do know something about basic math.

He says he will ask the blonde waitress an integral, and the first laughingly agrees.

The second man calls over the waitress and asks `what is the integral of x squared?'.

The waitress says `one third x cubed' and while walking away, turns back and says over her shoulder `plus a constant'!

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A tribe of Native Americans generally referred to their woman by the animal hide with which they made their blanket. Thus, one woman might be known as Squaw of Buffalo Hide, while another might be known as Squaw of Deer Hide. This tribe had a particularly large and strong woman, with a very unique (for North America anyway) animal hide for her blanket. This woman was known as Squaw of Hippopotamus hide, and she was as large and powerful as the animal from which her blanket was made.

Year after year, this woman entered the tribal wrestling tournament, and easily defeated all challengers; male or female. As the men of the tribe admired her strength and power, this made many of the other woman of the tribe extremely jealous. One year, two of the squaws petitioned the Chief to allow them to enter their sons together as a wrestling tandem in order to wrestle Squaw of the Hippopotamus hide as a team. In this way, they hoped to see that she would no longer be champion wrestler of the tribe.

As the luck of the draw would have it, the two sons who were wrestling as a tandem met the squaw in the final and championship round of the wrestling contest. As the match began, it became clear that the squaw had finally met an opponent that was her equal. The two sons wrestled and struggled vigorously and were clearly on an equal footing with the powerful squaw. Their match lasted for hours without a clear victor. Finally the chief intervened and declared that, in the interests of the health and safety of the wrestlers, the match was to be terminated and that he would declare a winner.

The chief retired to his teepee and contemplated the great struggle he had witnessed, and found it extremely difficult to decide a winner. While the two young men had clearly outmatched the squaw, he found it difficult to force the squaw to relinquish her tribal championship. After all, it had taken two young men to finally provide her with a decent match. Finally, after much deliberation, the chief came out from his teepee, and announced his decision. He said...

"The Squaw of the Hippopotamus hide is equal to the sons of the squaws of the other two hides"

A topologist is a man who doesn't know the difference between a coffee cup and a doughnut.

A statistician can have his head in an oven and his feet in ice, and he will say that on the average he feels fine.

A guy decided to go to the brain transplant clinic to refreshen his supply of brains. The secretary informed him that they had three kinds of brains available at that time. Doctors' brains were going for $20 per ounce and lawyers' brains were getting $30 per ounce. And then there were mathematicians' brains which were currently fetching $1000 per ounce. "A 1000 dollars an ounce!" he cried. "Why are they so expensive?" "It takes more mathematicians to get an ounce of brains," she explained.

A topologist walks into a bar and orders a drink. The bartender, being a number theorist, says, "I'm sorry, but we don't serve topologists here."

The disgruntled topologist walks outside, but then gets an idea and performs Dahn surgery upon herself. She walks into the bar, and the bartender, who does not recognize her since she is now a different manifold, serves her a drink. However, the bartender thinks she looks familiar, or at least locally similar, and asks, "Aren't you that topologist that just came in here?"

To which she responds, "No, I'm a frayed knot."

There are three kinds of people in the world; those who can count and those who can't.

There are two groups of people in the world; those who believe that the world can be divided into two groups of people, and those who don't.

The world is divided into two classes: people who say "The world is divided into two classes", and people who say The world is divided into two classes: people who say: "The world is divided into two classes", and people who say: The world is divided into two classes: people who say ...

97.3% of all statistics are made up.

Did you hear the one about the statistician? Probably....

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Top ten excuses for not doing homework:

The guy gets on a bus and starts threatening everybody: "I'll integrate you! I'll differentiate you!!!" So everybody gets scared and runs away. Only one person stays. The guy comes up to him and says: "Aren't you scared, I'll integrate you, I'll differentiate you!!!" And the other guy says; "No, I am not scared, I am e^x."

Why did the cat fall off the roof? Because he lost his mu. (mew=sound cats make, mu=coeff of friction)

Boy's Life, May 1973:

Ralph: Dad, will you do my math for me tonight?
Dad: No, son, it wouldn't be right.
Ralph: Well, you could try.

Mrs. Johnson the elementary school math teacher was having children do problems on the blackboard that day.

``Who would like to do the first problem, addition?''

No one raised their hand. She called on Tommy, and with some help he finally got it right.

``Who would like to do the second problem, subtraction?''

Students hid their faces. She called on Mark, who got the problem but there was some suspicion his girlfriend Lisa whispered it to him.

``Who would like to do the third problem, division?''

Now a low collective groan could be heard as everyone looked at nothing in particular. The teacher called on Suzy, who got it right (she has been known to hold back sometimes in front of her friends).

``Who would like to do the last problem, multiplication?''

Tim's hand shot up, surprising everyone in the room. Mrs. Johnson finally gained her composure in the stunned silence. ``Why the enthusiasm, Tim?''

``God said to go fourth and multiply!''

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Definitions of Terms Commonly Used in Higher Maths

The following is a guide to the weary student of mathematics who is often confronted with terms which are commonly used but rarely defined. In the search for proper definitions for these terms we found no authoritative, nor even recognized, source. Thus, we followed the advice of mathematicians handed down from time immortal: "Wing It."

I don't want to write down all the "in- between" steps.
If I have to show you how to do this, you're in the wrong class.
I hope you weren't sleeping when we discussed this earlier, because I refuse to repeat it.
I shouldn't have to tell you this, but for those of you who erase your memory tapes after every test...
WLOG (Without Loss Of Generality):
I'm not about to do all the possible cases, so I'll do one and let you figure out the rest.
Even you, in your finite wisdom, should be able to prove this without me holding your hand.
This is the boring part of the proof, so you can do it on your own time.
I couldn't verify all the details, so I'll break it down into the parts I couldn't prove.
The hardest of several possible ways to do a proof.
Four special cases, three counting arguments, two long inductions, "and a partridge in a pair tree."
One third less filling (of the page) than your regular proof, but it requires two extra years of course work just to understand the terms.
Requires no previous knowledge of the subject matter and is less than ten lines long.
At least one line of the proof of this case is the same as before.
4 out of 5 mathematicians surveyed recommended this as the final form for their students who choose to finish.
TFAE (The Following Are Equivalent):
If I say this it means that, and if I say that it means the other thing, and if I say the other thing...
I don't remember how it goes (come to think of it I'm not really sure we did this at all), but if I stated it right (or at all), then the rest of this follows.
I'll leave out everything but the conclusion, you can't question 'em if you can't see 'em.
I'm running out of time, so I'll just write and talk faster.
I don't want to write it on the board lest I make a mistake.
Manipulate symbols by the rules without any hint of their true meaning (popular in pure math courses).
I can't find anything wrong with your proof except that it won't work if x is a moon of Jupiter (Popular in applied math courses).
Trust me, It's true.

Some famous mathematician was to give a keynote speech at a conference. Asked for an advance summary, he said he would present a proof of Fermat's Last Theorem -- but they should keep it under their hats. When he arrived, though, he spoke on a much more prosaic topic. Afterwards the conference organizers asked why he said he'd talk about the theorem and then didn't. He replied this was his standard practice, just in case he was killed on the way to the conference.

When I was a Math/Chem grad student at Princeton in 1973-74, there was a story going around about a grad student. This guy was always late. One day he stumbled into class late, saw seven problems written on the board, and wrote them down. As the week went on he began to panic: the math department at Princeton is fiercely competitive, and here he was unable to do most of a simple homework assignment! When the next class rolled around he only had solved two of the problems, although he had a pretty good idea of how to solve a third but not enough time to complete it.

When he dejectedly flung his partial assignment on the prof's desk, the prof asked him "What's that?" "The homework." "What homework?" Eventually it came out that what the prof had written on the board were the seven most important unsolved problems in the field.

This is largely an academic legend, at least according to Jan Harold Brunvand, the author of a series of books on so-called Urban Legends. He talks about it in his latest book _Curses! Broiled Again!_ in the chapter entitled "The Unsolvable Math Problem." It is, however, based in some fact. The Stanford mathematician, George B. Danzig, apparently managed to solve two statistics problems previously unsolved under similar circumstances.

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The following problem can be solved either the easy way or the hard way.

Two trains 200 miles apart are moving toward each other; each one is going at a speed of 50 miles per hour. A fly starting on the front of one of them flies back and forth between them at a rate of 75 miles per hour. It does this until the trains collide and crush the fly to death. What is the total distance the fly has flown?

The fly actually hits each train an infinite number of times before it gets crushed, and one could solve the problem the hard way with pencil and paper by summing an infinite series of distances. The easy way is as follows: Since the trains are 200 miles apart and each train is going 50 miles an hour, it takes 2 hours for the trains to collide. Therefore the fly was flying for two hours. Since the fly was flying at a rate of 75 miles per hour, the fly must have flown 150 miles. That's all there is to it.

When this problem was posed to John von Neumann, he immediately replied, "150 miles."

"It is very strange," said the poser, "but nearly everyone tries to sum the infinite series."

"What do you mean, strange?" asked Von Neumann. "That's how I did it!"

Mathematicians are like Frenchmen: whatever you say to them, they translate it into their own language, and forthwith it means something entirely different. -- Johann Wolfgang von Goethe

"The reason that every major university maintains a department of mathematics is that it is cheaper to do this than to institutionalize all those people."

Three mathematicians and a physicist walk into a bar. You'd think the second one would have ducked. (Ha, that quack's me up!)

Q: What do you call a young eigensheep?
A: A lamb, duh!!!

"The world is everywhere dense with idiots." - LFS

A math/computer science convention was being held. On the train to the convention, a bunch of math majors and a bunch of computer science majors were on the train. Each of the math majors had his/her train ticket. The group of computer science majors had only ONE ticket for all of them. The math majors started laughing and snickering.

Then, one of the CS majors said "here comes the conductor" and then all of the CS majors went into the bathroom. The math majors were puzzled. The conductor came aboard and said "tickets please" and got tickets from all the math majors. He then went to the bathroom and knocked on the door and said "ticket please" and the CS majors stuck the ticket under the door. The conductor took it and then the CS majors came out of the bathroom a few minutes later. The math majors felt really stupid.

So, on the way back from the convention, the group of math majors had one ticket for the group. They started snickering at the CS majors, for the whole group had no tickets amongst them. Then, the CS major lookout said "Conductor coming!". All the CS majors went to the bathroom. All the math majors went to another bathroom. Then, before the conductor came on board, one of the CS majors left the bathroom, knocked on the other bathroom, and said "ticket please."

The following is supposedly a true story about Russell. It isn't really a math joke since it makes fun of the British hierarchy, but it's funny anyway....

Around the time when Cold War started, Bertrand Russell was giving a lecture on politics in England. Being a leftist in a conservative women's club, he was not received well at all: the ladies came up to him and started attacking him with whatever they could get their hands on. The guard, being an English gentleman, did not want to be rough to the ladies and yet needed to save Russell from them. He said, "But he is a great mathematician!" The ladies ignored him. The guard said again, "But he is a great philosopher!" The ladies ignore him again. In desperation, finally, he said, "But his brother is an earl!" Bert was saved.

Another "true" story, kinda like the aforementioned urban legend:

Enrico Fermi, while studying in college, was bored by his math classes. He walked up to the professor and said, "My classes are too easy!" The professor looked at him, and said, "Well, I'm sure you'll find this interesting." Then the professor copied 9 problems from a book to a paper and gave the paper to Fermi. A month later, the professor ran into Fermi, "So how are you doing with the problems I gave you?" "Oh, they are very hard. I only managed to solve 6 of them." The professor was visibly shocked, "What!? But those are unsolved problems!"


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