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### Re: Amusing answers to tests

Posted: **Wed Nov 21, 2007 12:44 am UTC**

by **PaulT**

By the way, the Niels Bohr story was missing my favourite method of determining the height of the building: you find the site manager and offer him this shiny new barometer if he'll tell you the height of the building.

### Re: Amusing answers to tests

Posted: **Wed Nov 21, 2007 12:46 am UTC**

by **Mathmagic**

PaulT wrote:By the way, the Niels Bohr story was missing my favourite method of determining the height of the building: you find the site manager and offer him this shiny new barometer if he'll tell you the height of the building.

The story wrote:"But since we are constantly being exhorted to exercise independence of mind and apply scientific methods, undoubtedly the best way would be to knock on the janitor's door and say to him 'If you would like a nice new barometer, I will give you this one if you tell me the height of this skyscraper'."

Same difference.

### Re: Amusing answers to tests

Posted: **Wed Nov 21, 2007 1:15 am UTC**

by **McHell**

Or in other words: what site manager? Are they spawned at the creation of a building and then hang around forever?

I also heard it as <janitor>, but thought <architect> might be more useful. I couldn't even figure out what the janitors said, after a year, they were nice guys who always tried to start smalltalk -- but then, it was Glasgow...

### Re: Amusing answers to tests

Posted: **Wed Nov 21, 2007 2:34 am UTC**

by **miles01110**

skeptical scientist wrote:So, at my undergraduate institution, all students were supposed to take a certain number of courses labeled "writing intensives". A "writing intensive" course was not just a course which involved writing, but also involved the possibility of revision and the professor going to the effort of getting the class certified as a "writing intensive" so they were few and far between, and mostly uninteresting.

We're undergraduate institution buddies, it would seem.

I took that class too. The only thing I learned was how much I can't stand pure math

### Re: Amusing answers to tests

Posted: **Wed Nov 21, 2007 6:30 am UTC**

by **pi-3 orionis**

On a math project due tomarrow a problem says to find the derivatives of sinhx coshx and tanhx. I was tempted to just find it in the book and write a page number down as to actually writing proofs.

### Re: Amusing answers to tests

Posted: **Wed Nov 21, 2007 8:02 am UTC**

by **quintopia**

McHell wrote:Gravitational? I don't see how that works. On the other hand, the obvious thing here is that the ideal pendulum's period scales linearly with its length (and not much at all its mass)... Bohr would have got that right.

I heard the same story told by a phys prof, but not attributed to any existing person (it also doesn't get funnier by having happened or not).

Fix'd!

Remember that T~2π√(

^{l}/

_{g})

And, of course,

g=

G^{me}/

_{r2}Put these together and you can calculate the difference between two heights at which a pendulum is swung given the difference in the period of its swing at the two heights. Granted, you'd need a reliable way of measuring such minute differences in time, and a very large sample size, but the basic idea is sound. The real question is why it took him a long page to derive the formula. It could be done in a few lines.

Edit: I just realized why the formula would be so long. . .in order to get accurate results, the formula would have to address the shape of the Earth. . .it's not exactly a point mass.

### Re: Amusing answers to tests

Posted: **Wed Nov 21, 2007 8:13 am UTC**

by **notzeb**

Probably because he calculated the exact period, using elliptic integrals.

### Re: Amusing answers to tests

Posted: **Wed Nov 21, 2007 11:50 am UTC**

by **evilbeanfiend**

quintopia wrote:Edit: I just realized why the formula would be so long. . .in order to get accurate results, the formula would have to address the shape of the Earth. . .it's not exactly a point mass.

if you are outside a sphere the gravity you 'see' is the same for a point, of course the earth is not exactly a sphere either...

### Re: Amusing answers to tests

Posted: **Wed Nov 21, 2007 8:13 pm UTC**

by **ptveite**

I have a couple here....

First, if I don't know exactly how to do a proof in a math class, I will usually write a bunch of stuff that's true and assert that the rest is trivial. It actually works pretty often.

Second, and more interestingly, I took very accelerated math through a program at our local university, and was in calc I in 8th grade, so when we got to half-lives in my 8th grade science class and there was one question about finding the exact amount of a radioactive isotope left between two even half-lives, I set up a differential equation to find an exact equation for the amount remaining - I knew at the time that all that they wanted me to do was average the two results for the half-lives on either side, but thought that was stupid and knew it was wrong. The answer that I got was the correct answer. My teacher marked it wrong, and I got up in front of the class and explained, as best I could to a bunch of 8th graders, exactly what I had done. He said "Well, that's interesting, but still wrong" and i didn't get the credit for the problem. I love that i was smarter in 8th grade than my teacher, who clearly had no idea what was going on.

### Re: Amusing answers to tests

Posted: **Wed Nov 21, 2007 11:26 pm UTC**

by **PaulT**

mathmagic wrote:PaulT wrote:By the way, the Niels Bohr story was missing my favourite method of determining the height of the building: you find the site manager and offer him this shiny new barometer if he'll tell you the height of the building.

The story wrote:"But since we are constantly being exhorted to exercise independence of mind and apply scientific methods, undoubtedly the best way would be to knock on the janitor's door and say to him 'If you would like a nice new barometer, I will give you this one if you tell me the height of this skyscraper'."

Same difference.

Dammit! I looked through the story three times to check it wasn't there!

### Re: Amusing answers to tests

Posted: **Thu Nov 22, 2007 1:06 am UTC**

by **Buttons**

It's still missing

my favorite, though.

esmerel.com wrote:7. Find a barometer with heights of local buildings on itGo to all the local gift shops. Look for a fancy souvenir barometer, the kind which shows important local landmarks. Find one which shows the heights of local buildings and considers this building important enough to be listed. Use this barometer.

### Re: Amusing answers to tests

Posted: **Thu Nov 22, 2007 3:45 am UTC**

by **pi-3 orionis**

ptveite wrote:

Second, and more interestingly, I took very accelerated math through a program at our local university, and was in calc I in 8th grade, so when we got to half-lives in my 8th grade science class and there was one question about finding the exact amount of a radioactive isotope left between two even half-lives, I set up a differential equation to find an exact equation for the amount remaining - I knew at the time that all that they wanted me to do was average the two results for the half-lives on either side, but thought that was stupid and knew it was wrong. The answer that I got was the correct answer. My teacher marked it wrong, and I got up in front of the class and explained, as best I could to a bunch of 8th graders, exactly what I had done. He said "Well, that's interesting, but still wrong" and i didn't get the credit for the problem. I love that i was smarter in 8th grade than my teacher, who clearly had no idea what was going on.

That reminds me of the time in 2nd grade where my teacher marked me wrong for spelling colour with a "u". I don't think I'll ever forget that.

### Re: Amusing answers to tests

Posted: **Thu Nov 22, 2007 9:30 am UTC**

by **2ndFloor**

Not all math, but funny.

High School Biology test (during the unit on populations and such)

Question: Given (blah), (blah blah), and (blah blah blah), explain why the deer population rose exponentially from time A to time B.

My Answer: "It was the free love era."

High School Calculus test (with partners)

Question: extremely hard thing we had no idea how to do.

My partner's answer, written on our test: "Wanna go out on Friday?"

Best part: we forgot to erase it, so the teacher thought he was asking her out. We don't know what her response was.

High School European History test (male teacher)

Question: Explain why Queen Elizabeth was not deposed, in less than 100 words.

My answer: "Because she was hot, but also kinda scary. Like you."

### Re: Amusing answers to tests

Posted: **Thu Nov 22, 2007 10:15 pm UTC**

by **Yakk**

ptveite wrote:Second, and more interestingly, I took very accelerated math through a program at our local university, and was in calc I in 8th grade, so when we got to half-lives in my 8th grade science class and there was one question about finding the exact amount of a radioactive isotope left between two even half-lives, I set up a differential equation to find an exact equation for the amount remaining - I knew at the time that all that they wanted me to do was average the two results for the half-lives on either side, but thought that was stupid and knew it was wrong. The answer that I got was the correct answer. My teacher marked it wrong, and I got up in front of the class and explained, as best I could to a bunch of 8th graders, exactly what I had done. He said "Well, that's interesting, but still wrong" and i didn't get the credit for the problem. I love that i was smarter in 8th grade than my teacher, who clearly had no idea what was going on.

If they are at adjacent half-lives, then at time A there will be X and at time B there will be X/2.

At time C which is half way between A and B, there will be X/sqrt(2) left.

I don't see much need for a differential equation here? It is just K*2^-t/H.

### Re: Amusing answers to tests

Posted: **Fri Nov 23, 2007 5:36 am UTC**

by **gmalivuk**

Yakk wrote:ptveite wrote:Second, and more interestingly, I took very accelerated math through a program at our local university, and was in calc I in 8th grade, so when we got to half-lives in my 8th grade science class and there was one question about finding the exact amount of a radioactive isotope left between two even half-lives, I set up a differential equation to find an exact equation for the amount remaining - I knew at the time that all that they wanted me to do was average the two results for the half-lives on either side, but thought that was stupid and knew it was wrong. The answer that I got was the correct answer. My teacher marked it wrong, and I got up in front of the class and explained, as best I could to a bunch of 8th graders, exactly what I had done. He said "Well, that's interesting, but still wrong" and i didn't get the credit for the problem. I love that i was smarter in 8th grade than my teacher, who clearly had no idea what was going on.

If they are at adjacent half-lives, then at time A there will be X and at time B there will be X/2.

At time C which is half way between A and B, there will be X/sqrt(2) left.

I don't see much need for a differential equation here? It is just K*2^-t/H.

The impression I got, though, was that the teacher wanted students to take the arithmetic mean of the two quantities, instead of the geometric mean.

### Re: Amusing answers to tests

Posted: **Fri Nov 23, 2007 6:12 am UTC**

by **ptveite**

gmalivuk wrote:The impression I got, though, was that the teacher wanted students to take the arithmetic mean of the two quantities, instead of the geometric mean.

Wat he said. You're right, my method was not exactly efficient, altho it was right. The point is that the teacher was just retarded and had no idea what was going on.

### Re: Amusing answers to tests

Posted: **Fri Nov 23, 2007 10:39 pm UTC**

by **Yakk**

It was also unconvincing.

The half-life equation of Q(t) = K*2^(t/H) is simple and expresses "half of it goes away every H time".

Then you can solve for K, or abstract it out, and show pretty easily

and convincingly what the right result is.

A proof is a formal argument -- and an argument that fails to convince fails.

### Re: Amusing answers to tests

Posted: **Fri Nov 23, 2007 11:51 pm UTC**

by **Govalant**

A friend of mine used today the aliens one, on a Chemistry final. I showed it to him yesterday and today he was so temped to do it.

Anyway, the exercise was to write the Lewis structure of some substances and he wrote "I can't do it, the damn aliens stole my electrons!"

### Re: Amusing answers to tests

Posted: **Sat Nov 24, 2007 10:35 am UTC**

by **skeptical scientist**

ptveite wrote:Second, and more interestingly, I took very accelerated math through a program at our local university, and was in calc I in 8th grade, so when we got to half-lives in my 8th grade science class and there was one question about finding the exact amount of a radioactive isotope left between two even half-lives, I set up a differential equation to find an exact equation for the amount remaining - I knew at the time that all that they wanted me to do was average the two results for the half-lives on either side, but thought that was stupid and knew it was wrong. The answer that I got was the correct answer. My teacher marked it wrong, and I got up in front of the class and explained, as best I could to a bunch of 8th graders, exactly what I had done. He said "Well, that's interesting, but still wrong" and i didn't get the credit for the problem. I love that i was smarter in 8th grade than my teacher, who clearly had no idea what was going on.

Nice one. Your teacher got totally owned. Unfortunately all of my high school teachers were quite good (fancy private high school - my physics and chem teacher had a PhD) so I never had a chance to pull something like this. The closest I came was on a physics test where I used one correct method to work out an answer, my teacher used a different one, and we came to different answers. I discussed this with my teacher and we figured out that the question itself described an impossible physical situation - an elastic collision where kinetic energy was not conserved. (So he initially marked it wrong and then gave me credit when we figured out what the problem was.)

0SpinBoson wrote:Since I was told I had to give a quiz the day after the exam to preserve the integrity of the schedule, I had the following question on my Physics II quiz (note that this is electromagnetism without calculus):

Derive, using Maxwell's equations, the speed of light in terms of the fundamental constants e0 and u0.

I got answers ranging from question marks to:

A drawing of an apple tree, with the text "I like apples. I like apples"

"You take the first equation, multiply by a kangaroo and subtract a bowl of soup."

What would you have done if one of your students showed that one class of solutions to Maxwell's equations were plane waves with a given relationship between frequency and wavelength, and then worked out the speed as frequency*wavelength using e

_{0} and u

_{0}?

### Re: Amusing answers to tests

Posted: **Sat Nov 24, 2007 9:55 pm UTC**

by **Pathway**

skeptical scientist wrote:0SpinBoson wrote:Since I was told I had to give a quiz the day after the exam to preserve the integrity of the schedule, I had the following question on my Physics II quiz (note that this is electromagnetism without calculus):

Derive, using Maxwell's equations, the speed of light in terms of the fundamental constants e0 and u0.

I got answers ranging from question marks to:

A drawing of an apple tree, with the text "I like apples. I like apples"

"You take the first equation, multiply by a kangaroo and subtract a bowl of soup."

What would you have done if one of your students showed that one class of solutions to Maxwell's equations were plane waves with a given relationship between frequency and wavelength, and then worked out the speed as frequency*wavelength using e

_{0} and u

_{0}?

Mark it correct?

### Re: Amusing answers to tests

Posted: **Sun Nov 25, 2007 1:58 am UTC**

by **Supergrunch**

Phi wrote:So, these aren't really in lieu of answers to questions I don't know, but I do tend to doodle on my tests. One one of my previous tests in Physics, there was a problem about some child pulling a few blocks tied together by string, and it was asking the tension force between the two blocks. I solved the problem using half of the space, and then used the other half to draw a picture of a monster pulling the blocks, saying, "GRARR! The friction monster is here to screw you over!"

One of my favorite drawings, though, was a small comic. There are two guys talking, and there's a rope hanging in the air. "Dude, check it out, it's my massless rope!" The other guy replies "Oh nice! Did you bring your frictionless pulley?". The next panel involves the two standing there with nothing between them, and guy1 saying "Yeah, but the radius is negligible."

Once, though, I did some very stupid mistake on a test, and ended up with an odd integral. All that I wrote as the answer was "word."

This reminds me of what some people wrote in exams my my school (both were GCSEs, which you take at 15/16 so it's fairly basic stuff)

There was one physics question with a diagram demonstrating the expanding universe, with several little galaxy cartoons and arrows on them radiating outwards. One guy answered the question correctly then joined up all the lines and marked the point where they met "centre of the universe".

There was also a maths paper where the position of sunken treasure in a lake was defined by several loci, which you were supposed to plot on the the diagram and shade the area with the treasure. After doing it someone wrote "harr be treasurreee!!!" at the side.

Anyway, I think the only time I lost a mark for being right was on a chemistry mock, where they had these questions worth about 5 marks that they expected you to write a short paragraph for, with one of the marks being for "spelling and grammar" or something. I wrote the answer to one in a single sentence, which was actually 2 sentences joined with a semi-colon, but contained all the correct points. However, the mark scheme said that a minimum of 2 sentences was necessary for the spelling and grammar mark, so I lost it... for using a semi-colon correctly. They refused to give me the mark however much I appealed... I suppose it's not surprising though, as I think the teacher always got "its" and "it's" muddled up.

### Re: Amusing answers to tests

Posted: **Sun Nov 25, 2007 10:02 pm UTC**

by **Lleu**

On a geometry final, I was asked to perform a certain glide reflection. However, the transformations given were a rotation and a translation. I refused to answer due to ethical reasons.

### Re: Amusing answers to tests

Posted: **Mon Nov 26, 2007 2:38 am UTC**

by **adlaiff6**

Lleu wrote:On a geometry final, I was asked to perform a certain glide reflection. However, the transformations given were a rotation and a translation. I refused to answer due to ethical reasons.

What ethical reasons might those be?

### Re: Amusing answers to tests

Posted: **Mon Nov 26, 2007 3:05 am UTC**

by **Yakk**

adlaiff6 wrote:Lleu wrote:On a geometry final, I was asked to perform a certain glide reflection. However, the transformations given were a rotation and a translation. I refused to answer due to ethical reasons.

What ethical reasons might those be?

It would violate her chosen orientation!

### Re: Amusing answers to tests

Posted: **Mon Nov 26, 2007 3:58 am UTC**

by **3.14159265...**

Well not so much test, but one of my math profs who I work closely with, is awsome, here is something he said the other day. He is also always late.

"I am never late, because If I was late, that would mean I came to class after class had started, but I have always arrived just as class started, so I am always on time."

adlaiff6 you still have that siggi, you just made my month!

### Re: Amusing answers to tests

Posted: **Mon Nov 26, 2007 6:16 am UTC**

by **andqso**

Not a math problem, but an amusing answer:

Our school requires seniors in the AP English class to sit for the AP exam whether they want to or not. One of my friends had already been accepted to a school that didn't give any sort of credit for the AP English test, so he decided he might as well entertain himself. Instead of writing an essay, he covered the page with an anatomically accurate, exquisitely detailed, ejaculating penis (and he's a pretty serious artist, so he could pull it off). I can only imagine what the grader must have thought.

### Re: Amusing answers to tests

Posted: **Mon Nov 26, 2007 1:41 pm UTC**

by **btilly**

andqso wrote:Not a math problem, but an amusing answer:

Our school requires seniors in the AP English class to sit for the AP exam whether they want to or not. One of my friends had already been accepted to a school that didn't give any sort of credit for the AP English test, so he decided he might as well entertain himself. Instead of writing an essay, he covered the page with an anatomically accurate, exquisitely detailed, ejaculating penis (and he's a pretty serious artist, so he could pull it off). I can only imagine what the grader must have thought.

Oh, that reminds me of a good story.

First some history. Most people do not realize that what we think of as the women's liberation movement was actually the

second women's liberation movement. The first was back in the 1800s, and its long-term successes include that women have the vote and can wear pants. But for a time it also resulted in many women working in what had been men's professions.

This story is set at McGill's medical school in the 1920s when women were losing ground again. There was a medical school class with one woman in it, and the professor clearly wished there were none. So he kept on trying to make her life difficult. Finally one day he asked her to diagram a male penis on the board while he kept on lecturing. So she drew as he talked.

He noticed the class giggling. He turned around. She had diagrammed an erect penis. He said, "That is

not the usual state which we diagram a penis in!" She replied, "It is the only state that I've seen a penis in. Perhaps you'd care to show me one in a different state?"

Afterwards, that professor stopped trying to give that medical student a hard time.

PS Disclaimer, I heard this story from a highschool teacher and cannot substantiate it. But the overall history is accurate.

### Re: Amusing answers to tests

Posted: **Mon Nov 26, 2007 3:17 pm UTC**

by **jestingrabbit**

andqso wrote:(and he's a pretty serious artist, so he could pull it off).

I don't normally do this but THAT'S WHAT SHE SAID!!

### Re: Amusing answers to tests

Posted: **Wed Nov 28, 2007 2:16 pm UTC**

by **Ended**

jestingrabbit wrote:I don't normally do this

That's what your mum said last night.

### Re: Amusing answers to tests

Posted: **Wed Nov 28, 2007 5:17 pm UTC**

by **oxoiron**

When I used to teach a GenChem lab, one of the questions in one section asked the students to name 10 things in which lead is used.

Every semester, at least half of them would answer "pencils".

### Re: Amusing answers to tests

Posted: **Wed Nov 28, 2007 6:38 pm UTC**

by **Supergrunch**

oxoiron wrote:When I used to teach a GenChem lab, one of the questions in one section asked the students to name 10 things in which lead is used.

Every semester, at least half of them would answer "pencils".

Reminds me of a confusing question I got once.

"Give an example of a lead compound."

"Er... PbO but what does that have to do with the quest- ooooohhh..."

### Re: Amusing answers to tests

Posted: **Thu Nov 29, 2007 5:28 pm UTC**

by **Joseph**

My AP Biology exam had a question that was basically "Describe the process of photosynthesis in detail." My response was to write the theme song to "Daria." If only I had the artistic chops to draw her as well...

P.S. I got a 2 on the AP, surprising a grand total of zero people.

### Re: What proofs are (split from amusing test answers)

Posted: **Fri Nov 30, 2007 10:44 pm UTC**

by **SimonM**

Not so much amusing, but on my BMO today, I was so tired by the end I wrote

"Lemming 1"

and for one question, which was clearly complicated.. "this is trivial"

### Re: Amusing answers to tests

Posted: **Sat Dec 01, 2007 4:00 am UTC**

by **Aradae**

I know this has already been referenced in this thread but I just simply had to post it. This version has an extra touch of epicness.

The following is an actual question given on a University of Washington chemistry mid-term. The answer by one student was so "profound" that the professor shared it with colleagues, via the Internet, which is, of course, why we now have the pleasure of

enjoying it as well.

Bonus Question: Is Hell exothermic (gives off heat) or endothermic (absorbs heat)?

Most of the students wrote proofs of their beliefs using Boyle's Law (gas cools when it expands and heats when it is compressed) or some variant.

One student, however, wrote the following:

First, we need to know how the mass of Hell is changing in time. So we need to know the rate at which souls are moving into Hell and t he rate at which they are leaving. I think that we can safely assume that once a soul gets to Hell, it will not leave. Therefore, no souls are leaving.

As for how many souls are entering Hell, let's look at the different religions that exist in the world today. Most of these religions state that if you are not a member of their religion, you will go to Hell. Since there is more than one of these religions and since people do not belong to more than one religion, we can project that all souls go to Hell.

With birth and death rates as they are, we can expect the number of souls in Hell to increase exponentially. Now, we look at the rate of change of the volume in Hell because Boyle's Law states that in order for the temperature and pressure in Hell to stay the same, the volume of Hell has to expand proportionately as souls are added.

This gives two possibilities:

1. If Hell is expanding at a slower rate than the rate at which souls enter Hell, then the temperature and pressure in Hell will increase until all Hell breaks loose.

2. If Hell is expanding at a rate faster than the increase of souls in Hell, then the temperature and pressure will drop until Hell freezes over.

So which is it?

If we accept the postulate given to me by Teresa during my Freshman year that, "it will be a cold day in Hell before I sleep with you", and take into account the fact that I slept with her last night, then number two must be true, and thus I am sure that Hell is exothermic and has already frozen over. The corollary of this theory is that since Hell has frozen over, it follows that it is not accepting any more souls and is therefore, extinct...leaving only Heaven thereby proving the existence of a divine being which explains why, last night, Teresa kept shouting "Oh my God."

THIS STUDENT RECEIVED THE ONLY "A"

### Re: Amusing answers to tests

Posted: **Sat Dec 01, 2007 7:53 am UTC**

by **Akira**

You know, I wonder how Teresa felt about all this.

"Hey, Theresa! You slept with that nerd?? I thought you said you would never!"

"What?"

"See, here! I found this on the Internet. That's totally The Nerd's style of writing. You slept with him!!!"

".....DAMN.... <_<"

### Re: Amusing answers to tests

Posted: **Sat Dec 01, 2007 12:17 pm UTC**

by **Aradae**

It's not actually true, there are numerous versions of the story and most where the student doesn't get lucky.

I just find this version of the story the funniest.

### Re: Amusing answers to tests

Posted: **Sat Dec 01, 2007 5:55 pm UTC**

by **imatrendytotebag**

btilly wrote:Afterwards, that professor stopped trying to give that medical student a hard time.

...literally!

I have never put a silly answer on a test, but I did hear a pretty great story about a kid at my school who was taking the AP Calc test, and for one of the free response problems just drew a guy vomiting numbers.

### Re: Amusing answers to tests

Posted: **Sun Dec 02, 2007 11:48 am UTC**

by **itsatumbleweed**

A buddy of mine was working on a Number Theory test on which there was a problem that was set up around a 'real world' type situation. I'm a bit fuzzy on the details, but the question involved a census taker asking about the ages of people at a certain residence, with constraints on what the ages could be given the address. There were three possible answers for the ages:

75, 5, 3

15, 12, 7

25, 15, 10

My friend had *no* idea how to pick which one was the right answer mathematically, so he justified as follows:

75, 5, and 3 cannot be the right answer, because someone of 75 years is far too old to be the primary caregiver to a 5 year old and a 3 year old.

15, 12, and 7 couldn't be the answer, because a 15 year old could not possibly be the proprietor of his own home; there are laws against this sort of thing

Therefore, the answer is 25, 15, 10

He got credit (thought probably not full) because he got it down to 3 options, and because 25, 15, and 10 *actually* was the right answer, but the professor read the test out to all of his other classes making sure to note how ridiculous the logic was.

### Re: Amusing answers to tests

Posted: **Sun Dec 02, 2007 12:06 pm UTC**

by **btilly**

The answer I was proudest of was a final exam for my second analysis course. It was an oral. I forget the exact question, but it was something along the lines of, "Is the product of two Lebesgue integrable functions Lebesgue integrable?"

My answer was, "I don't know, but I would guess that the answer is 'No' and the counter-example is hard. Why? Well I know it is not in the text, but from the way you asked it you know there is an answer. If it was true and had an easy proof, the proof would be in the text. If it was true and had a hard proof, the result would be mentioned in the text. If it was false and had an easy counter-example, the counter-example would be in the text. So the only case where nothing would be said would be if it was false and had a hard counter-example."

The professor said that I was absolutely right, and in all of the years that he'd been giving the course I was the only person to figure that out. Then he told me where I could find the article giving the difficult counter-example.

### Re: Amusing answers to tests

Posted: **Sun Dec 02, 2007 5:57 pm UTC**

by **Torn Apart By Dingos**

btilly wrote:The professor said that I was absolutely right, and in all of the years that he'd been giving the course I was the only person to figure that out. Then he told me where I could find the article giving the difficult counter-example.

What is the counter-example? Also, what text did you use?