Challenge Questions Blog

### Challenge Questions

So do you have a Challenge Question that could stump the community? Then submit the question with the "correct" answer and we'll post it. If it's really good, we may even roll it up to Specs & Techs. You'll be famous!

Answers to Challenge Questions appear by the last Tuesday of the month.

 Previous in Blog: Four Dogs Squared: November 2021 challenge question Next in Blog: CR4 Challenge Question: Big clock in a New Year (Jan. 2022)

# CR4 Challenge Question: Remember, no googleing (Dec. 2021)

Posted November 30, 2021 12:00 AM
Pathfinder Tags: challenge question

Interested in this topic? By joining CR4 you can "subscribe" to

11
Guru

Join Date: Apr 2010
Location: About 4000 miles from the center of the earth (+/-100 mi)
Posts: 9257
#1

### Re: CR4 Challenge Question: Remember, no googoling (Dec. 2021)

11/30/2021 8:07 AM

The product would be zero. One of the factors is (X-X).

Guru

Join Date: Sep 2009
Location: Louisville, OH
Posts: 1574
#3

### Re: CR4 Challenge Question: Remember, no googoling (Dec. 2021)

12/02/2021 12:15 PM

Don't think so. True for X=1 or X=2, but not the rest.

If no googling, how about DuckDuckGoing, or any of the multiple search engines?

__________________
Lehman57
Score 1 for Off Topic
2
Guru

Join Date: Jul 2006
Location: Eastern Kansas USA
Posts: 1446
#4

### Re: CR4 Challenge Question: Remember, no googoling (Dec. 2021)

12/02/2021 3:56 PM

Since X is not otherwise defined as a separate unknown, it has to be defined as one value in the series of A=... through X=..., Y=..., and Z=.... So the answer is correct as pointed out already.

--JMM

Guru

Join Date: Dec 2008
Location: Long Island NY
Posts: 15290
#5

### Re: CR4 Challenge Question: Remember, no googoling (Dec. 2021)

12/05/2021 11:15 PM

The imaginary number, i, was created to find the square root of negative numbers. Was a number ever fabricated so that number multiplied by zero would produce a non-zero number? If there is such a number I wonder what kind of mathematics would find this useful, possibly something in Georg Cantor's set theory work or probabilities?

__________________
"Don't disturb my circles." translation of Archimedes last words
Off Topic (Score 5)
Guru

Join Date: Aug 2005
Posts: 5499
#6

### Re: CR4 Challenge Question: Remember, no googling (Dec. 2021)

12/06/2021 5:41 AM

Have you heard of calculus?

Calculus kind of relies on the fact that ∞ x 0 = anything you want it to

__________________
We are alone in the universe, or, we are not. Either way it's incredible... Adapted from R. Buckminster Fuller/Arthur C. Clarke
Guru

Join Date: Dec 2008
Location: Long Island NY
Posts: 15290
#7

### Re: CR4 Challenge Question: Remember, no googling (Dec. 2021)

12/06/2021 9:01 AM

L'Hopitals rule is well known to me. I've cited it here at CR4 many times. Do you know why it doesn't apply to the original puzzle?

I believe it also does not apply to my query for a singular number to multiply with zero and get a real number as the imaginary number set provides an answer for negative number square roots. Infinity (∞) is not really a singular number but an indeterminant placeholder. I believe Georg Cantor developed multiple forms of infinity and worked in set theory too.

__________________
"Don't disturb my circles." translation of Archimedes last words
Guru

Join Date: Aug 2005
Posts: 5499
#11

### Re: CR4 Challenge Question: Remember, no googling (Dec. 2021)

12/13/2021 10:32 AM

From the dim and distant past I seem to remember that all of mathematics (or perhaps just number theory) can be derived from five basic assumptions.

I think that your plan for a number which when multiplied by zero equals a non zero real number would fall foul of those assumptions. But what if it were possible to tweak those assumptions so that the number was possible.

I found Peano's axioms on Wikipedia: I don't think they are the ones I remembered but are sort of similar. I can't see any way to tweak them.

I also found this, which literally made me Laugh Out Loud for ages:-

__________________
We are alone in the universe, or, we are not. Either way it's incredible... Adapted from R. Buckminster Fuller/Arthur C. Clarke
Guru

Join Date: Apr 2010
Location: About 4000 miles from the center of the earth (+/-100 mi)
Posts: 9257
#8

### Re: CR4 Challenge Question: Remember, no googoling (Dec. 2021)

12/06/2021 8:36 PM

I think physicists call it renormalization.

Off Topic (Score 4)
Guru

Join Date: Dec 2008
Location: Long Island NY
Posts: 15290
#9

### Re: CR4 Challenge Question: Remember, no googoling (Dec. 2021)

12/06/2021 10:24 PM

Oh my.

I jumped down that rabbit hole with my normal Wikipedia link, followed by a few other associated journals, and quickly developed a headache. What did come quickly to my mind was Peter Woit's writing "Not Even Wrong"(a book I highly recommend). I realize this rabbit hole has nothing to do with string theory (I think) but the rapid complexity made me wonder if intellects were hiding behind convoluted terminology.

Multiplying zero with anything to get something was not obvious to me but it might be in there somewhere. To be fair, Georg Cantor's work can be just as baffling if one is not properly prepared.

__________________
"Don't disturb my circles." translation of Archimedes last words
Off Topic (Score 5)
Guru

Join Date: Apr 2010
Location: About 4000 miles from the center of the earth (+/-100 mi)
Posts: 9257
#10

### Re: CR4 Challenge Question: Remember, no googoling (Dec. 2021)

12/07/2021 9:46 PM

This describes renormalization in simple terms that I can sort of understand...

Some calculations, such as the mass of the electron, come out to be infinite when using the theory to take into account all of the virtual particles (photons), so they give up and plug in the measured value.

(It seems like cheating to me, but I'm just an amateur.)

https://www.britannica.com/science/renormalization

Off Topic (Score 5)
Anonymous Poster #1
#15

### Re: CR4 Challenge Question: Remember, no googoling (Dec. 2021)

12/20/2021 11:19 AM

And bingo was his name-o!

Well done.

Guru

Join Date: Oct 2014
Location: Hemet, Land of milk and honey.
Posts: 2365
#2

### Re: CR4 Challenge Question: Remember, no googoling (Dec. 2021)

12/02/2021 11:10 AM

It appears that you can't use the mathematical expression where 1 googol = 1.0 x 10/100 as a greund to form the derivative of the question.

Score 1 for Off Topic
Associate

Join Date: Mar 2021
Posts: 29
#12

### Re: CR4 Challenge Question: Remember, no googoling (Dec. 2021)

12/14/2021 9:52 AM

It would be 0, because in the order you will reach ...(X-W)*(X-X)*(X-Y)... where

X-X=0 and then - everything multiplied by 0 is 0!

Guru

Join Date: Aug 2005
Posts: 5499
#13

### Re: CR4 Challenge Question: Remember, no googoling (Dec. 2021)

12/15/2021 6:41 AM

"everything multiplied by 0 is 0!"

But.... but... but.. 0 factorial is 1

__________________
We are alone in the universe, or, we are not. Either way it's incredible... Adapted from R. Buckminster Fuller/Arthur C. Clarke
Associate

Join Date: Mar 2021
Posts: 29
#14

### Re: CR4 Challenge Question: Remember, no googoling (Dec. 2021)

12/15/2021 7:35 AM

No "but... but... but...", no factorials-mactorials, no integrals and etc. Simple math problem for 3rd grade! 2*0=0; 0*7=0; (5-3)*(2-2)*(8-4)=2*0*4=0.

Interested in this topic? By joining CR4 you can "subscribe" to