20091111, 18:46  #1 
I quite division it
"Chris"
Feb 2005
England
31×67 Posts 
Chocolate
You have a bar of chocolate that has 32 squares arranged as 4 x 8. What is the minimum number of breaks that will turn this into its individual squares?
Rules: No melting, freezing, cutting, sawing, use of ultrasound, WMDs, particle accelerators etc. Snapping with the fingers in the traditional manner only. I will not accept responsibility for any injury, death, loss etc. Last fiddled with by Flatlander on 20091111 at 18:47 
20091111, 18:54  #2  
Nov 2003
7460_{10} Posts 
Quote:
with one break into two 4x4 squares. Can I then place one on top of the other and do another break (i.e. break both at once) to get 4 2x4 rectangles? Can I then stack them and break again? etc. 

20091111, 19:01  #3 
I quite division it
"Chris"
Feb 2005
England
2077_{10} Posts 
No 'stacking' allowed.

20091111, 19:05  #4 
Jan 2009
Ireland
186_{10} Posts 
Bob, i was thinking the same thing. Whats the saying, Great minds think alike.
my guess,just working it out in my head is 31 
20091111, 19:10  #5 
Aug 2006
3×1,993 Posts 

20091111, 19:14  #6 
"Ben"
Feb 2007
2^{9}·7 Posts 
How big are the squares? If the bar is appreciably bigger than my hand then I probably couldn't do it with my guess below.
10 
20091111, 19:16  #7 
Jul 2006
Calgary
5^{2}·17 Posts 
31

20091111, 19:17  #8 
Nov 2003
2^{2}·5·373 Posts 

20091111, 20:43  #9 
"Jacob"
Sep 2006
Brussels, Belgium
3^{2}×197 Posts 
What is a "break" ? Even without stacking if one takes the bar in hands and pushes on a inner square, in one movement there are many fractures...
If a "break" of one piece results in two pieces only, I agree the answer should be 31. Jacob 
20091111, 21:14  #10 
I quite division it
"Chris"
Feb 2005
England
31×67 Posts 
I meant a clean, straightline break. But I think this has run its course now.
There are at least 4 conclusions: 1) Each clean, straightline break results in one more piece. So the answer is 31. (Which is annoying and why I don't share my chocolate.) 2) Generous mathematicians have broken nails and strong hands from repeatedly trying to use the optimum 'Binary Method'. 3) They consider this to be "the traditional manner". 4) Defining a well posed puzzle is quite hard. 
20091112, 00:58  #11 
Undefined
"The unspeakable one"
Jun 2006
My evil lair
2^{2}×3×17×31 Posts 
I find that sticking a bar in my back pocket and then sitting down tends to create many pieces in just one 'breaking event'.
And later, sitting on a radiator long enough will put it back into 'one piece' again. 
Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Hands off our Chocolate!  ewmayer  Soap Box  2  20070625 21:47 