CTK Exchange
CTK Wiki Math
Front Page
Movie shortcuts
Personal info
Awards
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 Search CTK Buying a book is a commitment to learning Table of content Products to download and subscription Things you can find on CTK Chronology of updates Email to Cut The Knot Recommend this page

CTK Exchange

Subject: "Cutting a torus (2nd attempt)"     Previous Topic | Next Topic
Printer-friendly copy     Email this topic to a friend    
Conferences The CTK Exchange This and that Topic #897
Reading Topic #897
itineracy
guest
Apr-30-09, 07:06 AM (EST)
 
"Cutting a torus (2nd attempt)"
 
   In a well-known puzzle, Martin Gardner asked for the maximum number of pieces into which a torus could be sliced by three planes. Based on the formula X(n)=(n^3+3n^2+8n)/6 for n planes, the answer is given as 13.
The formula however, assumes the torus to be a solid, where I thought a torus was supposed to be a surface.
Now, when slicing the torus in such a way that it would produce 13 pieces if it were a donut, it actually produces 14 pieces if it were an inner tube.

Q: Does anyone know the inner tube formula? Or how to obtain it through mathematical rigor?


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

Conferences | Forums | Topics | Previous Topic | Next Topic

You may be curious to have a look at the old CTK Exchange archive.
Please do not post there.

Copyright © 1996-2018 Alexander Bogomolny

Search:
Keywords:

Google
Web CTK