Math Jokes

I haven't invented these jokes - I just collect them from Volker Runde's website.

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!"

A math student is pestered by a classmate who wants to copy his homework assignment. The student hesitates, not only because he thinks it's wrong, but also because he doesn't want to be sanctioned for aiding and abetting.
His classmate calms him down: "Nobody will be able to trace my homework to you: I'll be changing the names of all the constants and variables: a to b, x to y, and so on."
Not quite convinced, but eager to be left alone, the student hands his completed assignment to the classmate for copying.
After the deadline, the student asks: "Did you really change the names of all the variables?"
"Sure!" the classmate replies. "When you called a function f, I called it g; when you called a variable x, I renamed it to y; and when you were writing about the log of x+1, I called it the timber of x+1..."

Q: What does the zero say to the the eight?
A: Nice belt!

The math teacher asks his students: "What is 9 times 7?"
He gets several answers - all are either 62 or 65.
"Come on - the correct answer can either be 62 or 65!"

"That math prof's marriage is falling apart!"
"No wonder! He's into scientific computing - and she's incalculable!"

Q: How does one insult a mathematician?
A: You say: "Your brain is smaller than any >0!"

Q: What does a mathematician present to his fiancée when he wants to propose?
A: A polynomial ring!

The chef instructs his apprentice: "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!"

A woman in a bar tries to pick up a mathematician.
"How old, do you think, am I?" she asks coyly.
"Well - 18 by that fire in your eyes, 19 by that glow on your cheeks, 20 by that radiance of your face, and adding that up is something you can probably do for yourself..."

Q: What is the most erotic number?
A: 2110593!
Q: Why?
A: When 2 are 1 and don't pay at10tion, they'll know within 5 weeks whether or not, after 9 months, they'll be 3...

Theorem. A cat has nine tails.

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

Q: What do you get if you add two apples and three apples?
A: A high school math problem!

Trigonometry for farmers: swine and coswine...

Q: What is the difference between a mathematician and a philosopher?
A: The mathematician only needs paper, pencil, and a trash bin for his work - the philosopher can do without the trash bin...

Q: What is a mathematician's pick when faced with the choice between poutine and eternal bliss in the afterlife?
A: Poutine! Because nothing is better than eternal bliss in the afterlife, and poutine is better than nothing.

Q: What is non-orientable and lives in the ocean?
A: Möbius Dick...

Two math students, a boy and his girlfriend, are going to a fair. They are in line to ride the ferris wheel when it shuts down.
The boy says: "It's a sin for those people to keep us waiting like this!"
The girl replies: "No - it's a cosin, silly!!!"

Life is complex: it has both real and imaginary components.

The math professor just accepted a new position at a university in another city and has to move. He and his wife pack all their belongings into cardboard boxes and have them shipped off to their new home. To sort out some family matters, the wife stays behind for a few more days while her husband has already left for their new residence.
The boxes arrive when the wife still hasn't rejoined her husband. When they talk on the phone in the evening, she asks him to count the boxes, just to make sure the movers didn't loose any of them.
"Thirty nine boxes altogether", says the prof on the phone.
"That can't be", the wife exclaims. "The movers picked up forty boxes at our old place."
The prof counts once again, but again his count only reaches 39.
The next morning, the wife calls the moving company and complains. The company promises to check; a few hours later, someone calls back and reports that all forty boxes did arrive.
In the evening, when the prof and his wife are on the phone again, she asks: "I don't understand it. When you count, you get 39, and when they do, they get 40. That's more than strange..."
"Well", the prof says. "This is a cordless phone, so you can stay on the line and count with me: zero, one, two, three,..."

There are 10 kinds of mathematicians. Those who can think binarily and those who can't...

Q: What is the difference between a Ph.D. in mathematics and a large pizza?
A: A large pizza can feed a family of four...

New York (CNN). At John F. Kennedy International Airport today, a Caucasian male (later discovered to be a high school mathematics teacher) was arrested trying to board a flight while in possession of a compass, a protractor and a graphical calculator.
According to law enforcement officials, he is believed to have ties to the Al-Gebra network. He will be charged with carrying weapons of math instruction.

After her husband's death, the elderly lady decided to go back to school and get a degree in mathematics.
A few weeks into the term, she storms into the dean's office, exclaiming: "I've been silent until now - but I'm not going to take these obscenities anymore!"
"What obscenities are you talking about?"
She reaches into her purse and pulls out a notebook. "I noted of all of them. In my presence, professors had the complete lack of decency to speak of" - she leafs through her notebook - "Bruhat-Tits spaces, a pumping lemma, and even degenerate colonels!"

Two mathematicians are studying a convergent series.
The first one says: "Do you realize that the series converges even when all the terms are made positive?"
The second one asks: "Are you sure?"

Q: How can you tell that Harvard was planned by a mathematician?
A: The div school is right next to the grad school...

A mathematician is asked by a friend who is a devout Christian: "Do you believe in one God?"
He answers: "Yes - up to isomorphism."

Q: How does a mathematician induce good behavior in her children?
A: `I've told you n times, I've told you n+1 times...'

Q: Do you know any catchy anagram of Banach-Tarski?
A: Banach-Tarski Banach-Tarski...

"Students nowadays are so clueless", the math professor complains to a colleague. "Yesterday, a student came to my office hours and wanted to know if General Calculus was a Roman war hero..."

Mother to her daughter: "Why does the tablecloth you just put on the table have the word `truth' written on it?"
Daughter: "Because I want to turn the table into a truth table!"

A mathematician and his best friend, an engineer, attend a public lecture on geometry in thirteen-dimensional space.
"How did you like it?" the mathematician wants to know after the talk.
"My head's spinning", the engineer confesses. "How can you develop any intuition for thirteen-dimensional space?"
"Well, it's not even difficult. All I do is visualize the situation in arbitrary N-dimensional space and then set N = 13."

A newlywed husband is discouraged by his wife's obsession with mathematics. Afraid of being second fiddle to her profession, he finally confronts her: "Do you love math more than me?"
"Of course not, dear - I love you much more!"
Happy, although sceptical, he challenges her: "Well, then prove it!"
Pondering a bit, she responds: "Ok... Let epsilon be greater than zero..."

"So how's your boyfriend doing, the math student?"
"Don't mention that crazy pervert to me anymore! We broke up."
"How can you say such a nasty thing about him? He seemed to be such a nice boy."
"Imagine! He was restless during the days and couldn't sleep at night - always trying to solve his math problems. When he had finally done it, he wasn't happy: he would call himself a complete idiot and throw all his notes into the garbage. One day, I couldn't take it anymore, and I told him to drop math. You know what he told me?"
"He said, he enjoyed it!!!"

It is only two weeks into the term that, in a calculus class, a student raises his hand and asks: "Will we ever need this stuff in real life?"
The professor gently smiles at him and says: "Of course not - if your real life will consist of flipping hamburgers at MacDonald's!"

An American mathematician returns home from a conference in Moscow on real and complex analysis.
The immigration officer at the airport glances at his landing card and says: "So, your trip to Russia was business related. What's the nature of your business?"
"I am a professor of mathematics."
"What kind of mathematics are you doing?"
The professor ponders for a split second, trying to come up with something that would sound specific enough without making the immigration officer suspicious, and replies: "I am an analyst."
The immigration officer nods with approval: "I think it's great that guys like you go to Russia to help those poor ex-commies to get their stock market on its feet..."

An investment firm is hiring mathematicians. After the first round of interviews, three hopeful recent graduates - a pure mathematician, an applied mathematician, and a graduate in mathematical finance - are asked what starting salary they are expecting.
The pure mathematician: "Would $30,000 be too much?"
The applied mathematician: "I think $60,000 would be OK."
The math finance person: "What about $300,000?"
The personnel officer is flabberghasted: "Do you know that we have a graduate in pure mathematics who is willing to do the same work for a tenth of what you are demanding!?"
"Well, I thought of $135,000 for me, $135,000 for you - and $30,000 for the pure mathematician who will do the work."

Statistics Canada is hiring mathematicians. Three recent graduates are invited for an interview: one has a degree in pure mathematics, another one in applied math, and the third one obtained his B.Sc. in statistics.
All three are asked the same question: "What is one third plus two thirds?"
The pure mathematician: "It's one."
The applied mathematician takes out his pocket calculator, punches in the numbers, and replies: "It's 0.999999999."
The statistician: "What do you want it to be?"

A math professor, a native Texan, was asked by one of his students: "What is mathematics good for?"
He replied: "This question makes me sick! If you show someone the Grand Canyon for the first time, and he asks you `What's it good for?' What would you do? Well, you kick that guy off the cliff!"

In a speech to a gathering of mathematics professors from throughout the United States, George W. Bush warned the academics not to misuse their position to force their often extremist political views on young Americans. "It is my understanding", the president said, "that you are frequently teaching algebra classes in which your students learn how to solve equations with the help of radicals. I can't say that I approve of that..."

To appreciate this joke, you may find it useful to check out some information on George W. Bush, the 43rd president of the United States of America.

Denis Diderot was a French philosopher in the 18th century. He traveled Europe extensively, and on his travels also stopped at the Russian court in St. Petersburg. His wit and suave charm soon drew a large following among the younger nobles at the court - and so did his atheist philosophy. That worried empress Catherine the Great very much...
Swiss mathematician Leonhard Euler was working at the Russian court at that time, and unlike Diderot, he was a devout Christian. So, the empress asked him for help in dealing with the threat posed by Diderot.
Euler had himself introduced to Diderot as a man who had found a mathematical proof for the existence of God. With a stern face the mathematician confronted the philosopher: "Monsieur, (a+bn)/n = x holds! Hence, God exists. What is your answer to that?"
Quick-witted Diderot was speechless, was laughed at by his followers, and soon returned to France.

Three statisticians go hunting. When they see a rabbit, the first one shoots, missing it on the left. The second one shoots and misses it on the right.
The third one shouts: "We've hit it!"

Theorem. Every positive integer is interesting.

Proof. Assume towards a contradiction that there is an uninteresting positive integer. Then there must be a smallest uninteresting positive integer. But being the smallest uninteresting positive integer is interesting by itself. Contradiction!

Math problems? Call 1-800-[(10x)(13i)2]-[sin(xy)/2.362x].

Mathematicians never die - they only loose some of their functions.

Q: What is the value of the contour integral around Western Europe?
A: Zero.
Q: Why?
A: Because all poles are in Eastern Europe!

There were three medieval kingdoms on the shores of a lake. There was an island in the middle of the lake, over which the kingdoms had been fighting for years. Finally, the three kings decided that they would send their knights out to do battle, and the winner would take the island.
The night before the battle, the knights and their squires pitched camp and readied themselves for the fight. The first kingdom had 12 knights, and each knight had five squires, all of whom were busily polishing armor, brushing horses, and cooking food. The second kingdom had twenty knights, and each knight had 10 squires. Everyone at that camp was also busy preparing for battle. At the camp of the third kingdom, there was only one knight, with his squire. This squire took a large pot and hung it from a looped rope in a tall tree. He busied himself preparing the meal, while the knight polished his own armor.
When the hour of the battle came, the three kingdoms sent their squires out to fight (this was too trivial a matter for the knights to join in).
The battle raged, and when the dust had cleared, the only person left was the lone squire from the third kingdom, having defeated the squires from the other two kingdoms, thus proving that the squire of the high pot and noose is equal to the sum of the squires of the other two sides.

Q: What is sour, yellow, and equivalent to the axiom of choice...
A: Zorn's lemon...

Q: What is polite and works for the phone company?
A: A deferential operator...

Q: What is purple and commutative?
A: An abelian grape...

A mathematician organizes a raffle in which the prize is an infinite amount of money paid over an infinite amount of time. Of course, with the promise of such a prize, his tickets sell like hot cake.
When the winning ticket is drawn, and the jubilant winner comes to claim his prize, the mathematician explains the mode of payment: "1 dollar now, 1/2 dollar next week, 1/3 dollar the week after that..."

Q: What does the Ph.D. in math with a job say to the Ph.D. in math without a job?
A: `Paper or plastic?'

When Noah's ark had finally come to a rest on top of mount Ararat, and when the waters had receded, Noah and his family - along with all the animals - left the ark, and God told them to be fruitful and multiply upon the earth.
But after all those months under deck on an overcrowded ark, none of the animals was in the mood for sex anymore.
Noah, who knew all too well what God could do in his wrath if his creatures were disobedient, got desperate.
So, he tore down one of the ark's masts, cut it into pieces, and built a table out of the logs. Then he told one of the snakes to perform a lascivious dance on top of the table and made all the other animals gather around it. After a while the snake's seductive moves showed an effect: One animal after the other started rocking in the rhythm of the snake's dance, and one after the other sneaked off with its mate to more private places... Finally, the dancing snake and her mate were all alone, and they too disappeared.
And Noah was pleased that God's will would be heeded.

Q: What does this story from the book of Genesis teach us about math?
A: When you have to multiply, all you need are a log table and an adder!

Q: How do you make one burn?
A: Differentiate a log fire!

A math professor is talking to her little brother who just started his first year of graduate school in mathematics.
"What's your favorite thing about mathematics?" the brother wants to know.
"Knot theory."
"Yeah, me neither."

Q: How do you call the largest accumulation point of poles?
A: Warsaw!

A visitor at the Royal Tyrell Museum asks a museum employee: "Can you tell me how old the skeleton of that T-Rex is?"
"It is precisely 60 million and three years, two months, and eighteen days old."
"How can you know that with such precision?!"
"Well, when I started working here, one of the scientists told me that the skeleton was 60 million years old - and that was precisely three years, two months, and eighteen days ago..."

The math professor's six-year-old son knocks at the door of his father's study.
"Daddy", he says. "I need help with a math problem I couldn't do at school."
"Sure", the father says and smiles. "Just tell me what's bothering you."
"Well, it's a really hard problem: There are four ducks swimming in a pond, when two more ducks come and join them. How many ducks are now swimming in the pond?"
The professor stares at his son with disbelief: "You couldn't do that?! All you need to know is that 4 + 2 = 6!"
"Do you think, I'm stupid?! Of course, I know that 4 + 2 = 6. But what does this have to do with ducks!?"

"What is Pi?"
A mathematician: "Pi is the ratio of the circumference of a circle to its diameter."
A computer programmer: "Pi is 3.141592653589 in double precision."
A physicist: "Pi is 3.14159 plus or minus 0.000005."
An engineer: "Pi is about 22/7."
A nutritionist: "Pie is a healthy and delicious dessert!"

A mathematician and a stock broker go to the races to bet on horses. The broker suggests a bet of $10,000. That's too much for the mathematician's taste: First, he wants to understand the rules, have a look at the horses, etc.
"Don't worry", the broker says. "I know an empirical algorithm that allows me to find the number of the winning horse with absolute certainty."
This does not convince the mathematician.
"You are too theoretical!" the broker exclaims and puts his $10,000 on a horse.
The horse comes in first - making the broker even richer than he already is. The mathematician is baffled.
"What is your algorithm?" he wants to know.
"It's rather easy. I have two children, three and five years old. I add up their ages and bet on that number."
"But three plus five is eight - and that horse had number nine!"
"I told you that you're too theoretical! Didn't I just experimentally prove that my calculation is correct?!"

Q: What is the first derivative of a cow?
A: Prime Rib!

When the logician's little son refused again to eat his vegetables for dinner, the father threatened him: "If you don't eat your vegies, you won't get any ice-cream!"
The son, frightened at the prospect of not having his favorite dessert, quickly finished his vegetables.

What happened next?

After dinner, impressed that his son had eaten all his vegetables, the father sent his son to bed without any ice-cream...

"Statistics shows that most people are abnormal!"
"How that?"
"According to statistics, a normal person has one breast and one testicle..."

Four friends have been doing really well in their calculus class: they have been getting top grades for their homework and on the midterm. So, when it's time for the final, they decide not to study on the weekend before, but to drive to another friend's birthday party in another city - even though the exam is scheduled for Monday morning. As it happens, they drink too much at the party, and on Monday morning, they are all hung over and oversleep. When they finally arrive on campus, the exam is already over.
They go to the professor's office and offer him an explanation: "We went to our friend's birthday party, and when we were driving back home very early on Monday morning, we suddenly had a flat tire. We had no spare one, and since we were driving on backroads, it took hours until we got help."
The professor nods sympathetically and says: "I see that it was not your fault. I will allow you to make up for the missed exam tomorrow morning."
When they arrive early on Tuesday morning, the students are put by the professor in a large lecture hall and are seated so far apart from each other that, even if they tried, they had no chance to cheat. The exam booklets are already in place, and confidently, the students start writing.
The first question - five points out of one hundred - is a simple exercise in integration, and all four finish it within ten minutes.
When the first of them has completed the problem, he turns over the page of the exam booklet and reads on the next one:

Problem 2 (95 points out of 100): Which tire went flat?

A stats professor plans to travel to a conference by plane. When he passes the security check, they discover a bomb in his carry-on-baggage. Of course, he is hauled off immediately for interrogation.
"I don't understand it!" the interrogating officer exclaims. "You're an accomplished professional, a caring family man, a pillar of your parish - and now you want to destroy that all by blowing up an airplane!"
"Sorry", the professor interrupts him. "I had never intended to blow up the plane."
"So, for what reason else did you try to bring a bomb on board?!"
"Let me explain. Statistics shows that the probability of a bomb being on an airplane is 1/1000. That's quite high if you think about it - so high that I wouldn't have any peace of mind on a flight."
"And what does this have to do with you bringing a bomb on board of a plane?"
"You see, since the probability of one bomb being on my plane is 1/1000, the chance that there are two bombs is 1/1000000. If I already bring one, the chance of another bomb being around is actually 1/1000000, and I am much safer..."

At a press conference held at the White House, president George W. Bush accused mathematicians and computer scientists in the U.S. of misusing classroom authority to promote a Democratic agenda. "Every math or CS department offers an introduction to AlGore-ithms", the president complained. "But not a single one teaches GeorgeBush-ithms..."

To appreciate this joke, you may find it useful to check out some information on George W. Bush, the 43rd president of the United States of America.

Q: How do you call a one-sided nudie bar?
A: A Möbius strip club.

"Divide fourteen sugar cubes into three cups of coffee so that each cup has an odd number of sugar cubes in it."
"That's easy: one, one, and twelve."
"But twelve isn't odd!"
"It's an odd number of cubes to put in a cup of coffee..."

Do you know that 87.166253% of all statistics claim a precision of results that is not justified by the method employed?

Q: How can you tell that a mathematician is extroverted?
A: When talking to you, he looks at your shoes instead of at his.

When the math professor's wife returns home from work, she finds an envelope on the living room table. She opens it and finds a letter from her husband:

When the professor returns from the hotel shortly before midnight, he also finds an envelope in the living room. He opens it and reads:

Q: What does the little mermaid wear?
A: An algae-bra.

A mathematical biologist spends his vacation hiking in the Scottish highlands. One day, he encounters a shepherd with a large herd of sheep. One of these cuddly, woolly animals would make a great pet, he thinks...
"How much for one of your sheep?" he asks the shepherd.
"They aren't for sale", the shepherd replies.
The math biologist ponders for a moment and then says: "I will give you the precise number of sheep in your herd without counting. If I'm right, don't you think that I deserve one of them as a reward?"
The shepherd nods.
The math biologist says: "387".
The shepherd is silent for a while and then says: "You're right. I hate to loose any of my sheep, but I promised: One of them is yours. Have your pick!"
The math biologist grabs one of the animals, puts it on his shoulders, and is about to march on, when the shepherd says: "Wait! I will tell you what your profession is, and if I'm right I'll get the animal back."
"That's fair enough."
"You must be a mathematical biologist."
The man is stunned. "You're right. But how could you know?"
"That's easy: You gave me the precise number of sheep without counting - and then you picked my dog..."

A logician at Safeway.
"Paper or plastic?"
"Not 'not paper and not plastic'!"

"Isn't statistics wonderful?"
"How so?"
"Well, according to statistics, there are 42 million alligator eggs laid every year. Of those, only about half get hatched. Of those that hatch, three fourths of them get eaten by predators in the first 36 days. And of the rest, only 5 percent get to be a year old for one reason or another. Isn't statistics wonderful?"
"What's so wonderful about all that?"
"If it weren't for statistics, we'd be up to our asses in alligators!"

One day, Jesus said to his disciples: "The Kingdom of Heaven is like 3x squared plus 8x minus 9."
A man who had just joined the disciples looked very confused and asked Peter: "What, on Earth, does he mean by that?"
Peter replied: "Don't worry - it's just another one of his parabolas."

Q: What is the fundamental principle of engineering mathematics?
A: Every function has a Taylor series which converges to the function and breaks off after the linear term.

"Wasn't yesterday your and your wife's first wedding anniversary? What is it like having being married to a mathematician for a whole year?"
"She just filed for divorce..."
"I don't believe it! Did you forget about your wedding day?"
"No. Actually, on my way back home from work, I stopped at a flower store and bought a bouquet of red roses for my wife. When I came home, I gave her the roses and said: `I love you.'"
"So, what happened?!"
"Well, she took the roses, slapped them around my face, kicked me in the groin, and threw me out of our apartment..."
"What a bitch!"
"No, no... it's all my fault... I should have said: `I love you and only you.'."

A pure and an applied mathematician are asked to calculate 2 * 2.
The applied mathematician's solution: We have

2 * 2 = 2 *1/(1-1/2).

The second factor on the right hand side has a geometric series expansion

1/(1-1/2) = 1 + 1/2 +1/4 + 1/8 + ....

Cutting off the series after the second term yields the approximate solution

2 * 2 = 2 *(1 +1/2) = 3.

The pure mathematician's solution: We have

2 * 2 = (-2) *1/(1-3/2).

The second factor on the right hand side has a geometric series expansion

1/(1-3/2) = 1 + 3/2 +9/4 + 27/8 + ...,

which diverges. Hence, the solution to 2 * 2 does not exist.

A physics professor has been conducting experiments and has worked out a set of equations which seem to explain his data. Nevertheless, he is unsure if his equations are really correct and therefore asks a colleague from the math department to check them.
A week later, the math professor calls him: "I'm sorry, but your equations are complete nonsense."
The physics professor is, of course, disappointed. Strangely, however, his incorrect equations turn out to be surprisingly accurate in predicting the results of further experiments. So, he asks the mathematician if he was sure about the equations being completely wrong.
"Well", the mathematician replies, "they are not actually complete nonsense. But the only case in which they are true is the trivial one where the field is Archimedean..."

"The number you have dialed is imaginary. Please, rotate your phone by 90 degrees and try again..."

Q: Do you already know the latest stats joke?
A: Probably...

Q: Why do mathematicians often confuse Christmas and Halloween?
A: Because Oct 31 = Dec 25.

A mathematician gives a talk intended for a general audience. The talk is announced in the local newspaper, but he expects few people to show up because nobody who is not a mathematician will be able to make any sense of the title: Convex sets and inequalities.
To his surprise, the auditorium is crammed when his talk begins. After he has finished, someone in the audience raises his hand.
"But you said nothing about the actual topic of your talk!"
"What topic to you mean?"
"Well, the one that was announced in the paper: Convicts, sex, and inequality."

George W. Bush visits Algeria. As part of his program, he delivers a speech to the Algerian people: "You know, I regret that I have to give this speech in English. I would very much prefer to talk to you in your own language. But unfortunately, I was never good at algebra..."

To appreciate this joke, you may find it useful to check out some information on George W. Bush, the 43rd president of the United States of America.

At the end of his course on mathematical methods in optimization, the professor sternly looks at his students and says: "There is one final piece of advice I'm going to give you now: Whatever you have learned in my course - never ever try to apply it to your personal lives!"
"Why?" the students ask.
"Well, some years ago, I observed my wife preparing breakfast, and I noticed that she wasted a lot of time walking back and forth in the kitchen. So, I went to work, optimized the whole procedure, and told my wife about it."
"And what happened?!"
"Before I applied my expert knowledge, my wife needed about half an hour to prepare breakfast for the two of us. And now, it takes me less than fifteen minutes..."

A French mathematician's pick up line: "Voulez vous Cauchy avec moi?"

"My life is all arithmetic", the young businesswoman explains. "I try to add to my income, subtract from my weight, divide my time, and avoid multiplying..."

A graduate student of mathematics who used to come to the university on foot every day arrives one day on a fancy new bicycle.
"Where did you get the bike from?" his friends want to know.
"It's a `thank you' present", he explains, "from that freshman girl I've been tutoring. But the story is kind of weird..."
"Tell us!"
"Well", he starts, "yesterday she called me on the phone and told me that she had passed her math final and that she wanted to drop by to thank me in person. As usual, she arrived at my place riding her bicycle. But when I had let her in, she suddenly took all her clothes off, lay down on my bed, smiled at me, and said: `You can get from me whatever you desire!'"
One of his friends remarks: "You made a really smart choice when you took the bicycle."
"Yeah", another friend adds, "just imagine how silly you would have looked in a girl's clothes - and they wouldn't have fit you anyway!"

Q: What is normed, complete, and yellow?
A: A Bananach space...

A father who is very much concerned about his son's bad grades in math decides to register him at a catholic school. After his first term there, the son brings home his report card: He's getting "A"s in math.
The father is, of course, pleased, but wants to know: "Why are your math grades suddenly so good?"
"You know", the son explains, "when I walked into the classroom the first day, and I saw that guy on the wall nailed to a plus sign, I knew one thing: This place means business!"

At a conference, a mathematician proves a theorem.
Someone in the audience interrupts him: "That proof must be wrong - I have a counterexample to your theorem."
The speaker replies: "I don't care - I have another proof for it."

A mathematician has been invited to speak at a conference. His talk is announced as

Proof of the Riemann hypothesis.

When the conference actually takes place, he speaks about something completely different.
After his talk, a colleague asks him: "Did you find an error in your proof?"
He replies: "No - I never had one."
"But why did you make this announcement?"
"That's my standard precaution - in case I die on my way to the conference..."

The mother of already three is pregnant with her fourth child.
One evening, the eldest daughter says to her dad: "Do you know, daddy, what I've found out?"
"The new baby will be Chinese!"
"Yes. I've read in the paper that statistics shows that every fourth child born nowadays is Chinese..."

A math student and a computer science student are jogging together in a park when they hear a voice: "Please, help me!"
They stop and look. The voice belongs to a frog sitting in the grass.
"Please, help me!" the frog repeats. "I'm not really a frog: I'm an enchanted, beautiful princess. Kiss me, and the spell will be broken - and I will be yours forever..."
The CS student picks up the frog and examines it carefully from all sides - making not even an attempt to kiss it.
"You don't have to marry me", the frog continues frantically, "if you're afraid of the commitment. I'll do whatever you wish me to do if you just kiss me..."
The frog's voice is silenced, when the CS student puts the animal into the right pocket of his pants.
"But why don't you kiss her?!" the math student asks.
"You know", the CS student replies, "I simply don't have time for a girlfriend - but a frog that talks makes a really cool pet..."

Psychologists subject an engineer, a physicist, and a mathematician - a topologist, by the way - to an experiment: Each of them is locked in a room for a day - hungry, with a can of food, but without an opener; all they have is pencil and paper.
At the end of the day, the psychologists open the engineer's room first. Pencil and paper are unused, but the walls of the room are covered with dents. The engineer is sitting on the floor and eating from the open can: He threw it against the walls until it cracked open.
The physicist is next. The paper is covered with formulas, there is one dent in the wall, and the physicist is eating, too: He calculated how exactly to throw the can against the wall, so that it would crack open.
When the psychologists open the mathematician's room, the paper is also full of formulas, the can is still closed, and the mathematician has disappeared. But there are strange noises coming from inside the can...
Someone gets an opener and opens the can. The mathematician crawls out. "Damn! I got a sign wrong..."

A physicist, a statistician, and a (pure) mathematician go to the races and place bets on horses.
The physicist's horse comes in last. "I don't understand it. I have determined each horse's strength through a series of careful measurements."
The statistician's horse does a little bit better, but still fails miserably. "How is this possible? I have statistically evaluated the results of all races for the past month."
They both look at the mathematician whose horse came in first. "How did you do it?"
"Well", he explains. "First, I assumed that all horses were identical and spherical..."

A physicist, a mathematician and a computer scientist discuss what is better: a wife or a girlfriend.
The physicist: "A girlfriend. You still have freedom to experiment."
The mathematician: "A wife. You have security."
The computer scientist: "Both. When I'm not with my wife, she thinks I'm with my girlfriend. With my girlfriend it's vice versa. And I can be with my computer without anyone disturbing me..."

Q: What is a topologist?
A: A person who cannot tell a doughnut from a coffee mug.

"What happened to your girlfriend, that really cute math student?"
"She no longer is my girlfriend. I caught her cheating on me."
"I don't believe that she cheated on you!"
"Well, a couple of nights ago I called her on the phone, and she told me that she was in bed wrestling with three unknowns..."

A group of mathematicians and a group of engineers are traveling together by train to attend a conference on mathematical methods in engineering. Each engineer has a ticket whereas only one of the mathematicians has one. Of course, the engineers laugh at the unworldly mathematicians and look forward to the moment the conductor shows up.
Suddenly one of the mathematicians shouts: "Conductor coming!"
All the mathematicians disappear into one washroom.
The conductor checks the ticket of each engineer and then knocks at the washroom door: "Your ticket, please."
The mathematicians stick the one ticket they have under the door, the conductor checks it and leaves. A few minutes later, when it is safe, the mathematicians come out of the washroom. The engineers are impressed.
When the conference has come to an end, the engineers decide that they are at least as smart as the mathematicians and also buy just one ticket for the whole group. This time the mathematicians have no ticket at all...
Again one of the mathematicians shouts: "Conductor coming!".
All the engineers rush off to one washroom. One of the mathematicians goes to that washroom, knocks at the door, and says: "Your ticket, please..."

In the old days of the cold war, when it was very hard for Westerners to visit the Soviet Union, a British mathematician travels to Moscow to speak in the seminar of a famous Russian professor.
He starts his talk writing a theorem on the board. When he wants to prove it, the professor interrupts him: "This theorem is clear!"
The speaker is, of course, annoyed, but manages to conceal it. He continues his talk with a second theorem, but, again, when he wants to start with the proof, he is interrupted by his host: "This theorem is also clear!"
With a stern face, he writes a third theorem on the board and asks: "Is this theorem clear, too?!"
His host nods.
The visitor grins and says: "This theorem - is false..."

Some engineers are trying to measure the height of a flag pole. They only have a measuring tape and are quite frustrated trying to keep the tape along the pole: It falls down all the time.
A mathematician comes along and asks what they are doing. They explain it to him.
"Well, that's easy..."
He pulls the pole out of the ground, lays it down, and measures it easily.
After he has left, one of the engineers says: "That's so typical of these mathematicians! What we need is the height - and he gives us the length!"

A mathematician has spent years trying to prove the Riemann hypothesis - without success. Finally, he decides to sell his soul to the devil in exchange for a proof. The devil promises to deliver a proof within four weeks.
Four weeks pass, but nothing happens. Half a year later, the devil shows up again - in a rather gloomy mood.
"I'm sorry", he says. "I couldn't prove the Riemann hypothesis either. But" - and his face lightens up - "I think I found a really interesting lemma..."

Q: Was ist paradox an der Analysis?
A: Man faltet, um zu glätten...

The pun only works in German.

Q: How does a mathematician call his dog?
A: Cauchy - because it leaves a residue at every pole...

Two men are having a good time in a bar. Outside, there's a terrible thunderstorm. Finally, one of the men thinks that it's time to leave. Since he has drunk a lot, he decides to walk home.
"But aren't you afraid of being struck by lightning?" his friend asks.
"Not at all. Statistics shows that, in this part of the country, one person per year gets struck by lightning - and that one person died in the hospital three weeks ago."

After the phenomenal success of Viagra, Pfizer has come up with yet another pharmaceutical sensation: knowledge pills.
A student who is way behind in his English literature class, goes to the pharmacy, and asks the pharmacist if there are knowledge pills for English literature.
"Sure", the pharmacist replies.
The student buys one, swallows it, and hours later he knows everything there is to know about English literature. If it's that easy to acquire knowledge, he thinks, why waste hours wrecking your brains over boring textbooks? So, he gives up studying, and whenever an exam is near, he goes to the pharmacy and buys the right knowledge pill: biology, art history, world history - you name it.
When he has to take a math exam, he goes again to the pharmacy as asks for a knowledge pill for mathematics.
"Just wait a moment", the pharmacist says. He disappears in the back of his store and comes back with a pill of the size of a melon.
"But how am I supposed to swallow this?!" the student exclaims.
"Well, math has always been a little hard to swallow..."

In a class, a math professor claims that he can prove everything under the assumption that 1+1=1.
A student challenges him: "Then prove that you're the pope!"
He ponders for a moment and then replies: "I am one, and the pope is one. Therefore, the pope and I are one."

A mathematician, an engineer, and a computer scientist are vacationing together. They are riding in a car, enjoying the countryside, when suddenly the engine stops working.
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: "Why don't we just open the doors, slam them shut, and see if everything works again?"

Let epsilon be less than zero...

Not really a joke, but rather a mathematician detection device: Tell it at a party, and those who laugh must be mathematicians.

Two math professors are sitting in a pub.
"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: " C."

A mathematician, a physicist, and an engineer are asked to test the following hypothesis: All odd numbers greater than one are prime.
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..."

In a dark, narrow alley, a function and a differential operator meet:
"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."

Back in the old days - when slide rules were still the most sophisticated computing equipment available to scientists and engineers...
Engineering students are taking a math final. Of course, slide rules are not allowed. And, of course, someone is cheating and has brought a slide rule to the exam. He is hiding it under his desk, but the student sitting to his left - who is stuck on a difficult calculation - has noticed it.
"Hey", he whispers. "Can you help me? What's three times six?"
His classmate reaches for his slide rule, and after a few seconds replies: "Nineteen."
"Are you sure?"
The other student reaches again for his slide rule, and after another few seconds replies: "You're right. It's closer to eighteen - eighteen point three, to be precise."

Two men are sitting in the basket of a balloon. For hours, they have been drifting through a thick layer of clouds, and they have lost orientation completely. Suddenly, the clouds part, and the two men see the top of a mountain with a man standing on it.
"Hey! Can you tell us where we are?!"
The man doesn't reply. The minutes pass as the balloon drifts past the mountain. When the balloon is about to be swallowed again by the clouds, the man on the mountain shouts: "You're in a balloon!"
"That must have been a mathematician."
"He thought long and thoroughly about what to say. What he eventually said was irrefutably correct. And it was of no use whatsoever..."