Your Favorite Math/Logic Riddles?

shma asks: "Whether you're involved in the Sciences, Mathematics, or Engineering, you undoubtedly enjoy finding simple solutions to seemingly difficult problems. I'm sure you all have a favorite mind-bender, and who better to share it with than the Slashdot community? Post your own problems and try to solve others. Just one request: If you have figured out the solution, link to it in a post, rather than write it out where anyone can see it." What brain benders tickle your fancy? "Here's a sample to consider: You're in a dark room with 50 quarters, 18 of which are heads up. You are allowed to move around the coins or flip some or all of them, if you wish. Problem is, it's too dark to tell what you're moving or flipping (no, you can't figure it out by touch either). Your job is to split the coins into two groups, each of which has the same number of heads up coins. How do you accomplish this?"

Comments

FP

[Anonymous Coward]

FP!

Math and science are obsolete

[shanen]

Soduku drives you nuts? (Whatever "soduku" is?) Anyway, the puzzles of this modern age are things like how we (or BushCo claiming to be acting on our behalf) can cut taxes for the rich while spending billions on wars while ignoring and eliminating infrastructure spending like flood prevention and education without going bankrupt. And don't waste your time looking for the linked post with the answer. There ain't no answer on this side (the outside) of the funny farm.

Welcome to 2005 going on 1984 but with our final destination sometime around 1840...

Re:Petals of the Rose

[mondoterrifico]

Heh, yeah the name of the game had no impact on solving it for me either. I looked at it as a simple odd/even game.
I just saw that you could ignore the even dice completely, add up the odd dice, and subtract from that total however many odd dice there were.