Hard Puzzles. Like Butter.

My puzzle post generated more interest than expected. One night at Siggraph an ex-MetaCreations whiz kid foisted a number of them on me, but I can't I was really in good form. It's been a while since I've devoted a lot of time to these kinds of puzzles. Lately, outside from solving problems at work, most of my puzzle energy goes into Scrabble and NYT crosswords.

Anyhow, what follows is a puzzle / problem to which I don't know the answer. The first time I saw it was on Ronald Hoeflin's Mega Test, which was once published in Omni Magazine. Famous high scorers include Marilyn vos Savant and John Sununu.

I took the test and came up with an answer, but I never found out if my answer was correct. Relative to other questions on the test, I believe it was the question the fewest people answered correctly.



The Question: Suppose a cube of butter is sliced by five perfectly straight (i.e., planar) knife strokes, the pieces thereby formed never moving from their initial positions. What is the maximum number of pieces that can thereby be formed? (The figure to the right illustrates three knife strokes.)

Finally, if you want a whole pile if challenges such as this to bang your head against, check out Darryl Miyaguchi's Uncommonly Difficult IQ Tests. I don't believe the original Mega Test is available, but check out Ronald Hoeflin's other tests. The question above is still #12 on the Power Test.

Also, many by Rottus are a lot of fun too.