# 3 question IQ test - just for fun!



## martik777 (Mar 3, 2021)

The Cognitive Reflection Test (CRT) has been hailed as the world's shortest IQ test. Apparently, it only takes three questions to separate the Einsteins from the Homer Simpsons of this world.

The quiz, developed in Princeton in 2005 by psychologist Shane Frederick, is designed to test your ability to ignore your gut response and think slower and more rationally. Or in psychology-speak, how good are you at ignoring system 1 (intuition) thinking in favor of system 2 (analytic) thinking? To succeed in the CRT, you must spend time reflecting on your answer and question your intuitive response. 

Of course, to prove your genius you must get all three questions correct but speed also matters. Speedier answers is another sign of a higher IQ.

So, how smart are you really? Remember, the questions might not be quite as simple as they first seem. Even students at some of the world's top universities (including Yale and Harvard) failed to get all three answers correct in a 2003 study. In fact, only 17% achieved a perfect score. 

*The quiz*​1. A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much does the ball cost?

2. If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?

3. In a lake, there is a patch of lily pads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half of the lake? 



Here's the link for the answers: https://www.businessinsider.com/onl...tly-answer-the-worlds-shortest-iq-test-2018-5


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## Aukai (Mar 4, 2021)




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## Superburban (Mar 4, 2021)

I got them all right away. I asked them to my Wife, who got mad. Then I went and checked the answers, and got a chuckle from this.

$0.05 — There's a very good chance you guessed $0.10. The answer is actually a little less — a $0.05 ball plus a bat costing $1.05 will set you back $1.10. And, of course, $1.05 is exactly $1 more expensive than $0.05. *(A Princeton study found that people who responded $0.10 were "significantly" less patient than those who got the right answer.)*

If She reads this, I am dead.


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## Aukai (Mar 4, 2021)

PFFFT......


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## martik777 (Mar 4, 2021)

Superburban said:


> I got them all right away. I asked them to my Wife, who got mad. Then I went and checked the answers, and got a chuckle from this.
> 
> $0.05 — There's a very good chance you guessed $0.10. The answer is actually a little less — a $0.05 ball plus a bat costing $1.05 will set you back $1.10. And, of course, $1.05 is exactly $1 more expensive than $0.05. *(A Princeton study found that people who responded $0.10 were "significantly" less patient than those who got the right answer.)*
> 
> If She reads this, I am dead.


You might like this one: https://www.mensa.org/workout


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## homebrewed (Mar 4, 2021)

I got two of the three "official" answers, but I have a quibble about question #2.  Consider this:  suppose that the 5 widgets are the result of 5 SEQUENTIAL ops on those 5 machines.  Then it would, indeed, take 100 minutes to make 100 of them.  I looked at the question and saw ambiguity in the specification.  The answer in the link fleshes things out by indicating that each machine is a "widget" machine, but, being a (partial) machinist, I also considered the more likely scenario that each machine only does a part of the required operations needed to make a widget.

So there.


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## Ulma Doctor (Mar 4, 2021)

as a young man, after successfully landing a stupid jump on my bmx bicycle,
i was once told, by a grumpy old timer walking by, "boy -if brains were TNT, you wouldn't have enough to blow your nose".
it hasn't got much better since


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## Aukai (Mar 4, 2021)

If brains were gasoline, I wouldn't have enough to power an ants motor scooter around the inside circle of a Cheerio


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## mmcmdl (Mar 4, 2021)

I wanna know where you can by a bat for a buck ! The last Demarini bats were well over $300 and that was 10 years ago .


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## Braeden P (Mar 4, 2021)

hey I got them all right


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## vtcnc (Mar 4, 2021)

homebrewed said:


> I got two of the three "official" answers, but I have a quibble about question #2.  Consider this:  suppose that the 5 widgets are the result of 5 SEQUENTIAL ops on those 5 machines.  Then it would, indeed, take 100 minutes to make 100 of them.  I looked at the question and saw ambiguity in the specification.  The answer in the link fleshes things out by indicating that each machine is a "widget" machine, but, being a (partial) machinist, I also considered the more likely scenario that each machine only does a part of the required operations needed to make a widget.
> 
> So there.



I really don't like question #2 either. It allows way too much to interpretation for those that actually use machines to make widgets. It doesn't fit the trick question profile like the others do so well. 

The common person would never first wonder if the machines are in sequential, parallel or some other hybrid configuration or not.


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## Braeden P (Mar 4, 2021)

vtcnc said:


> I really don't like question #2 either. It allows way too much to interpretation for those that actually use machines to make widgets. It doesn't fit the trick question profile like the others do so well.
> 
> The common person would never first wonder if the machines are in sequential, parallel or some other hybrid configuration or not.


in school we have questions like that but there a hard to get it right because they don't say what configuration they are in.


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## vtcnc (Mar 4, 2021)

Braeden P said:


> in school we have questions like that but there a hard to get it right because they don't say what configuration they are in.


Most questions like this do not allow for creativity that is required to solve for real world problems. The point of academic questions like this in school is to get you to practice and flex your analytical muscles, so when the time comes that you get stuck on real world constraints - you are prepared to adapt and have an idea of where to start with the problem solving.


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## ArmyDoc (Mar 4, 2021)

The comment on the first answer is telling. *A Princeton study found that people who responded $0.10 were "significantly" less patient than those who got the right answer.* 
The implication being that If you are not very patient, there's a good chance you won't take the time to think about your answer or to double check it.  This applies to the other questions too.  

Of course, there is another possibility.  The problem could be that you are over-confident in your answers. (I think some people would call that arrogant.  I'm not mentioning my wife here, although for some reason she comes to mind...)  You assume you are good enough to know the answer even if other people don't.  Or possibly both...

Apparently I am both impatient and arrogant.  Hey, at least I admit it.  That's the first step, right?


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## brino (Mar 4, 2021)

Braeden P said:


> hey I got them all right



Braeden, Congratulations on the results......but aren't you too young for that animated gif.....unless it's root beer.....  

-brino


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## Braeden P (Mar 4, 2021)

brino said:


> Braeden, Congratulations on the results......but aren't you too young for that animated gif.....unless it's root beer.....
> 
> -brino


root beer floats only


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## Braeden P (Mar 4, 2021)




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## Peyton Price 17 (Mar 4, 2021)

I got all of them right. the machine one was hard to get through. My school said mine was 140( not bragging) but a ten-question one said it was 367? most of the online ones are so fake that it is funny.


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## macardoso (Mar 4, 2021)

Got 2/3. Apparently I was "significantly" less patient than those who got the right answer.


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## Peyton Price 17 (Mar 4, 2021)

macardoso said:


> Got 2/3. Apparently I was "significantly" less patient than those who got the right answer.


it took me a while to find it out. only 5 minutes on the first one


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## Watchwatch (Mar 4, 2021)

I got the bat question wrong. Too impatient to subtract $1-.10. Lol 


Sent from my iPhone using Tapatalk


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## FOMOGO (Mar 4, 2021)

Hey! I've got widgets to make. I don't have time for this crap. Mike


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## sdelivery (Mar 4, 2021)

Braeden P said:


> hey I got them all right


Aw...... shut up kid! lol‍


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## Braeden P (Mar 4, 2021)

sdelivery said:


> Aw...... shut up kid! lol‍


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## SLK001 (Mar 4, 2021)

martik777 said:


> 3. In a lake, there is a patch of lily pads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half of the lake?



I have a quibble about the third question.

Take a lily pad that is 2" in diameter.  After 48 days of doubling, the area covered by the lily pads will be:

(2 * π) * 2^48, or 1.768559 * 10^15 sq inches

or

12,281 billion square feet,

or

440,544 square miles.
​The surface area of the earth is:

4 * π * r^2, or 4 * π * (8500 miles * 5280 feet/mile * 12 inches/feet)^2, or 3.644837^18 sq inches

or

25,311,370 billion square feet,

or

907,920,399 square miles.
​The real question should be, how many days before all non-lily life is wiped out by the lilies?


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## brino (Mar 4, 2021)

SLK001 said:


> The real question should be, how many days before all non-lily life is wiped out by the lilies?



If they taste okay we're good.
If they are poison, we're doomed.

-brino


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## SLK001 (Mar 4, 2021)

brino said:


> If they taste okay we're good.
> If they are poison, we're doomed.
> 
> -brino



If they're not poison, we humans would have to develop a liking for everything lily in a very short time!


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## higgite (Mar 4, 2021)

All I have to say about it is, the guy who invented the test obviously wasn't a genius, but I'm sure he thought he was. Okay, I lied. That's not really all I have to say about it. Also, I'm glad to see it was "developed" at a private university, not a tax payer funded public school. I just hope he wasn't working on a Federal grant.

If a train left Chicago doing 100 mph....

Tom


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## Peyton Price 17 (Mar 4, 2021)

an electric train is going north at 60 miles an hour and the wind is blowing east at 40 miles per hour, what direction is the smoke going.


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## RJSakowski (Mar 4, 2021)

A fun fact about question #3.  If we assume that a lily pad is about 4" or 10cm across and we start with a single lily pad, what is the size of the lake?
Answer, the lake will have a a surface area of 2.8E12 m^2 or 2.8E6 sq. km (2,800,000 sq. km.).  The total surface are of the Great Lakes is 244,106 sq. km. so the size of the lake would be more than ten times the combined size of the Great Lakes.  One big lily pond!


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## SLK001 (Mar 4, 2021)

Peyton Price 17 said:


> an electric train is going north at 60 miles an hour and the wind is blowing east at 40 miles per hour, what direction is the smoke going.


Well, each individual smoke particle is going east at 40 MPH.  The entire smoke _trail _is creating a line that is SSE of the traveling train.


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## Peyton Price 17 (Mar 4, 2021)

SLK001 said:


> Well, each individual smoke particle is going east at 40 MPH.  The entire smoke _trail _is creating a line that is SSE of the traveling train.


no, because it is electric


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## SLK001 (Mar 4, 2021)

RJSakowski said:


> A fun fact about question #3.  If we assume that a lily pad is about 4" or 10cm across and we start with a single lily pad, what is the size of the lake?
> Answer, the lake will have a a surface area of 2.8E12 m^2 or 2.8E6 sq. km (2,800,000 sq. km.).  The total surface are of the Great Lakes is 244,106 sq. km. so the size of the lake would be more than ten times the combined size of the Great Lakes.  One big lily pond!



And both of our examples assumed a _*small *_lily pad!


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## RJSakowski (Mar 4, 2021)

SLK001 said:


> I have a quibble about the third question.
> 
> Take a lily pad that is 2" in diameter.  After 48 days of doubling, the area covered by the lily pads will be:
> 
> ...


One error, you used the diameter rather than the radius.  Also, googling the diameter, I got 7,917.5 miles. but whose counting?

For my calculation, I assumed that the lily pads weren't overlapping so therefore, each pad would occupy a 10 x 10 cm square.  The 10 cm was the result of my observation of local lily pads and rounding to a convenient size.  Now, if they were those giant lily pads over a meter in diameter, well then we would have a much more serious problem.


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## SLK001 (Mar 4, 2021)

Peyton Price 17 said:


> no, because it is electric



I'm not talking train smoke.  I'm talking about the cigarette and cigar smoke coming from the smoking car!


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## Peyton Price 17 (Mar 4, 2021)

SLK001 said:


> I'm not talking train smoke.  I'm talking about the cigarette and cigar smoke coming from the smoking car!


you got me there


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## RJSakowski (Mar 4, 2021)

Peyton Price 17 said:


> no, because it is electric


Perhaps the generator is shorting out?


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## SLK001 (Mar 4, 2021)

RJSakowski said:


> One error, you used the diameter rather than the radius.  Also, googling the diameter, I got 7,917.5 miles. but whose counting?
> 
> For my calculation, I assumed that the lily pads weren't overlapping so therefore, each pad would occupy a 10 x 10 cm square.  The 10 cm was the result of my observation of local lily pads and rounding to a convenient size.  Now, if they were those giant lily pads over a meter in diameter, well then we would have a much more serious problem.



Dah!  I should have used the area of a circle, or:

π * r^2​Since in my case, the area is simply "π", instead of (2 * π), my results are really half of what I stated.  Brain fart!


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## homebrewed (Mar 4, 2021)

The author's "definitive" answer to question #2 was based on an assumption that all readers would interpret it the way he wanted them to.  This is an example of what I have called "the destructive power of an unvetted assumption".  Or in popular, sarcastic terms:  "what POSSIBLY could go wrong???" .


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## Aukai (Mar 4, 2021)

I don't have time for this.....


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## Winegrower (Mar 4, 2021)

These questions are all old bromides that occur over and over.   Now that you have been through these answers, you're all geniuses the next time the quiz comes along.


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## JPar (Mar 4, 2021)

homebrewed said:


> I got two of the three "official" answers, but I have a quibble about question #2.  Consider this:  suppose that the 5 widgets are the result of 5 SEQUENTIAL ops on those 5 machines.  Then it would, indeed, take 100 minutes to make 100 of them.  I looked at the question and saw ambiguity in the specification.  The answer in the link fleshes things out by indicating that each machine is a "widget" machine, but, being a (partial) machinist, I also considered the more likely scenario that each machine only does a part of the required operations needed to make a widget.
> 
> So there.



I don't think it matters if the machines perform sequential operations, or if each machine manufactures complete widgets.  The problem states that 5 machines can make 5 widgets in 5 minutes.  100 machines can be thought of as 20 groups of 5 machines.  At the end of 5 minutes, each group will have made 5 widgets.  20 groups times 5 widgets per group equals 100 widgets in 5 minutes.
John


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## aliva (Mar 4, 2021)

You forgot the tax on the bat and ball


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## Buffalo21 (Mar 4, 2021)

Aukai said:


> If brains were gasoline, I wouldn't have enough to power an ants motor scooter around the inside circle of a Cheerio



my boss told one of my fellow workers, “ if I shoved your brains up a gnat’s a$$, it would be like putting a BB in a boxcar”, the kid did not seem to understand..................


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## SLK001 (Mar 4, 2021)

RJSakowski said:


> One error, you used the diameter rather than the radius.  Also, googling the diameter, I got 7,917.5 miles. but whose counting?



Yep... I now see *that *error, too.  Oh, well!


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## homebrewed (Mar 4, 2021)

JPar said:


> I don't think it matters if the machines perform sequential operations, or if each machine manufactures complete widgets.  The problem states that 5 machines can make 5 widgets in 5 minutes.  100 machines can be thought of as 20 groups of 5 machines.  At the end of 5 minutes, each group will have made 5 widgets.  20 groups times 5 widgets per group equals 100 widgets in 5 minutes.
> John


You are right.  I went into the weeds and never came out


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## Forty Niner (Mar 8, 2021)

I also got all of the questions correct in only a few minutes.  Used a pencil for the first one, but the last two were in the head almost instant.
BUT then, because I enjoyed the quiz, I started giving the test to family and friends.   It did't work out well for me.  None of my friends or family got more than one right and then they seemed to be offended when I told them I thought the questions were easy 8th grade level math.  Stupid me.


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## ericc (Mar 8, 2021)

Forty Niner said:


> I also got all of the questions correct in only a few minutes.  Used a pencil for the first one, but the last two were in the head almost instant.
> BUT then, because I enjoyed the quiz, I started giving the test to family and friends.   It did't work out well for me.  None of my friends or family got more than one right and then they seemed to be offended when I told them I thought the questions were easy 8th grade level math.  Stupid me.


It certainly can cause hostility.  I don't know why it should.  It doesn't matter how you answer these questions.

Your avatar reminds me of another test which does matter.  I suspect that anybody who scores poorly on this test won't express much hostility.  And someone who does well may just remain quiet with a thoughtful and perhaps slightly worried expression.  Look up MCI CDT.  If you can operate a dividing head with hole plates, you should be able to ace this test.


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