CTK Exchange
Front Page
Movie shortcuts
Personal info
Awards
Reciprocal links
Terms of use
Privacy Policy

Interactive Activities

Cut The Knot!
MSET99 Talk
Games & Puzzles
Arithmetic/Algebra
Geometry
Probability
Eye Opener
Analog Gadgets
Inventor's Paradox
Did you know?...
Proofs
Math as Language
Things Impossible
My Logo
Math Poll
Other Math sit's
Guest book
News sit's

Recommend this site

Manifesto: what CTK is about |Store| Search CTK Buying a book is a commitment to learning Table of content Things you can find on CTK Chronology of updates Email to Cut The Knot Recommend this page

CTK Exchange

Subject: "puzzle of 4 numbers"     Previous Topic | Next Topic
Printer-friendly copy     Email this topic to a friend    
Conferences The CTK Exchange Guest book Topic #296
Reading Topic #296
chopper
guest
Oct-27-03, 01:55 PM (EST)
 
"puzzle of 4 numbers"
 
   Hi.
I think it'should be interesting to everybody to solve this puzzle (I failed).
So you have to find 4 different integers that match the following conditions:
using one of them or any their combination (I mean sum, not anything else) you should get any number from 1 to 40. You cannot use in calculation of any number twice the same number from these four.
I hope I explained clearly the puzzle, so if you have answer I'll be very glad.
Thank you.


  Alert | IP Printer-friendly page | Edit | Reply | Reply With Quote | Top
alexb
Charter Member
1120 posts
Oct-27-03, 01:58 PM (EST)
Click to EMail alexb Click to send private message to alexb Click to view user profileClick to add this user to your buddy list  
1. "RE: puzzle of 4 numbers"
In response to message #0
 
   This is a known puzzle. I believe it goes by the name of Bachet's problem, except that you should allow the differences as well. With only the sums, the numbers 1, 2, 4, 8 give you the maximum of 15. But if you allow differences, then the numbers 1, 3, 9, 27 can represent any number from 1 through 40.


  Alert | IP Printer-friendly page | Edit | Reply | Reply With Quote | Top
Charles
guest
Nov-06-03, 06:48 PM (EST)
 
2. "RE: puzzle of 4 numbers"
In response to message #1
 
   I don't think it is possible to do it with just sums. I do, however, know it is possible with sums and differences (with numbers 1, 3, 9, and 27, like the previous user stated). If we just used sums, then we can only get to 15 by using numbers 1, 2, 4, and 8.


  Alert | IP Printer-friendly page | Edit | Reply | Reply With Quote | Top

Conferences | Forums | Topics | Previous Topic | Next Topic

You may be curious to visit the old Guest book.
Please do not post there.

|Front page| |Contents| |Store|

Copyright © 1996-2018 Alexander Bogomolny

[an error occurred while processing this directive]