Challenge Questions Blog

Challenge Questions

Stop in and exercise your brain. Talk about this month's Challenge from Specs & Techs or similar puzzles.

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)
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
15 comments
Rating: Comments: Nested

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

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

Reply

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
11
Rixter
Guru

Join Date: Apr 2010
Location: About 4000 miles from the center of the earth (+/-100 mi)
Posts: 9081
Good Answers: 1033
#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).

Reply Good Answer (Score 11)
Go to Next Good Answer
Lehman57
Guru
Engineering Fields - Nuclear Engineering - New Member

Join Date: Sep 2009
Location: Louisville, OH
Posts: 1537
Good Answers: 29
#3
In reply to #1

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
Reply Score 1 for Off Topic
2
jmueller
Guru

Join Date: Jul 2006
Location: Eastern Kansas USA
Posts: 1414
Good Answers: 121
#4
In reply to #3

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
Reply Good Answer (Score 2)
No more Good Answers.
redfred
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15134
Good Answers: 937
#5
In reply to #1

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
Reply Off Topic (Score 5)
Randall
Guru

Join Date: Aug 2005
Location: Hemel Hempstead, UK
Posts: 5317
Good Answers: 290
#6
In reply to #5

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
Reply
redfred
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15134
Good Answers: 937
#7
In reply to #6

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
Reply
Randall
Guru

Join Date: Aug 2005
Location: Hemel Hempstead, UK
Posts: 5317
Good Answers: 290
#11
In reply to #7

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
Reply
Rixter
Guru

Join Date: Apr 2010
Location: About 4000 miles from the center of the earth (+/-100 mi)
Posts: 9081
Good Answers: 1033
#8
In reply to #5

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

12/06/2021 8:36 PM

I think physicists call it renormalization.

Reply Off Topic (Score 4)
redfred
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15134
Good Answers: 937
#9
In reply to #8

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
Reply Off Topic (Score 5)
Rixter
Guru

Join Date: Apr 2010
Location: About 4000 miles from the center of the earth (+/-100 mi)
Posts: 9081
Good Answers: 1033
#10
In reply to #9

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
Reply Off Topic (Score 5)
Anonymous Poster #1
#15
In reply to #1

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

12/20/2021 11:19 AM

And bingo was his name-o!

Well done.
Reply
tonyhemet
Guru

Join Date: Oct 2014
Location: Hemet, Land of milk and honey.
Posts: 2366
Good Answers: 36
#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.
Reply Score 1 for Off Topic
Hameleon
Active Contributor

Join Date: Mar 2021
Posts: 21
#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!
Reply
Randall
Guru

Join Date: Aug 2005
Location: Hemel Hempstead, UK
Posts: 5317
Good Answers: 290
#13
In reply to #12

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
Reply
Hameleon
Active Contributor

Join Date: Mar 2021
Posts: 21
#14
In reply to #13

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.
Reply
Reply to Blog Entry 15 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
Copy to Clipboard

Users who posted comments:

Anonymous Poster (1); Hameleon (2); jmueller (1); Lehman57 (1); Randall (3); redfred (3); Rixter (3); tonyhemet (1)

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

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Section
General:
Go

Search this Blog
Challenge Questions:
Go

Recent Blog Entries

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (56 right now)
Show Members
Advertisement