Jump to content


Welcome to BrainDen.com - Brain Teasers Forum

Welcome to BrainDen.com - Brain Teasers Forum. Like most online communities you must register to post in our community, but don't worry this is a simple free process. To be a part of BrainDen Forums you may create a new account or sign in if you already have an account.
As a member you could start new topics, reply to others, subscribe to topics/forums to get automatic updates, get your own profile and make new friends.

Of course, you can also enjoy our collection of amazing optical illusions and cool math games.

If you like our site, you may support us by simply clicking Google "+1" or Facebook "Like" buttons at the top.
If you have a website, we would appreciate a little link to BrainDen.

Thanks and enjoy the Den :-)
Guest Message by DevFuse
 

Photo
- - - - -


  • Please log in to reply
8 replies to this topic

#1 unreality

unreality

    Senior Member

  • Members
  • PipPipPipPip
  • 6370 posts

Posted 15 January 2008 - 10:38 PM

I am thinking of a number.
It's absolute value is √29

but if you add 2 to the number...
it's absolute value is √53!

What is the number? (there is only one answer)
  • 0

#2 bonanova

bonanova

    bonanova

  • Moderator
  • PipPipPipPip
  • 5842 posts
  • Gender:Male
  • Location:New York

Posted 16 January 2008 - 05:07 AM

I am thinking of a number.
It's absolute value is √29

but if you add 2 to the number...
it's absolute value is √53!

What is the number? (there is only one answer)

Spoiler for Well let's do the obvious first.
I take "absolute value" to mean drop the MINUS SIGN if there is one.
Is that the correct interpretation?
  • 0
The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
- Bertrand Russell

#3 unreality

unreality

    Senior Member

  • Members
  • PipPipPipPip
  • 6370 posts

Posted 16 January 2008 - 10:48 PM

bonanova the answer spoiler is wrong (wow I thought I'd never ever ever ever ever say that...lol)... the answer is EXACTLY 2

and I use the usual definition of absolute value: DISTANCE FROM ZERO

and I was wrong- there are actually 2 solutions. Name them both. :P
  • 0

#4 roolstar

roolstar

    Advanced Member

  • Members
  • PipPipPip
  • 250 posts
  • Gender:Male

Posted 17 January 2008 - 01:22 PM

no there's only one solution...
  • 0

#5 EventHorizon

EventHorizon

    Senior Member

  • VIP
  • PipPipPipPip
  • 512 posts
  • Gender:Male

Posted 17 January 2008 - 10:44 PM

I am thinking of a number.
It's absolute value is √29

but if you add 2 to the number...
it's absolute value is √53!

What is the number? (there is only one answer)


Spoiler for solution

  • 0

#6 roolstar

roolstar

    Advanced Member

  • Members
  • PipPipPip
  • 250 posts
  • Gender:Male

Posted 17 January 2008 - 11:10 PM

Spoiler for solution


Spoiler for Don't think so...


So only one solution...
  • 0

#7 unreality

unreality

    Senior Member

  • Members
  • PipPipPipPip
  • 6370 posts

Posted 18 January 2008 - 02:53 AM

This is the solution:

Spoiler for answer


EDIT: for some reason the square root symbol became a question mark, so I changed it from the square root symbol to 'v'
  • 0

#8 bonanova

bonanova

    bonanova

  • Moderator
  • PipPipPipPip
  • 5842 posts
  • Gender:Male
  • Location:New York

Posted 20 January 2008 - 10:22 AM

Good one!
I usually think of magnitude or modulus of complex numbers.
But absolute value is used also.
  • 0
The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
- Bertrand Russell

#9 unreality

unreality

    Senior Member

  • Members
  • PipPipPipPip
  • 6370 posts

Posted 21 January 2008 - 01:30 AM

:D (okay pointless post, lol)
  • 0




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users