Wednesday, June 30, 2010


I've seen this one before and haven't solved it.  Go ahead and comment answers in the blog, but not on Buzz or else  people will see them.  I quote this one from, but I've seen it before in other places as well. 

Five pirates have obtained 100 gold coins and have to divide up the loot. The pirates are all extremely intelligent, treacherous and selfish (especially the captain).

The captain always proposes a distribution of the loot. All pirates vote on the proposal, and if half the crew or more go "Aye", the loot is divided as proposed, as no pirate would be willing to take on the captain without superior force on their side.
If the captain fails to obtain support of at least half his crew (which includes himself), he faces a mutiny, and all pirates will turn against him and make him walk the plank. The pirates start over again with the next senior pirate as captain.

What is the maximum number of coins the captain can keep without risking his life?

Wednesday, June 23, 2010

Dots and Lines

This is a very old one, and many of you may have seen it before.  I try to avoid posting puzzles with outside-the-box solutions, but I made an exception for this one.  Using 4 straight, connected lines, connect all 9 dots.

Wednesday, June 16, 2010

Heads and Tails

This is borrowed from and I don't know the solution.  Submit ideas in the comments section - maybe you'll get it before I do. 

There are twenty coins sitting on the table, ten are currently heads and ten are currently tails. You are sitting at the table with a blindfold and gloves on. You are able to feel where the coins are, but are unable to see or feel if they are heads or tails. You must create two sets of coins. Each set must have the same number of heads and tails as the other group. You can only move or flip the coins, you are unable to determine their current state. How do you create two even groups of coins with the same number of heads and tails in each group?  [Note: I assume you need a guaranteed method of getting even groups, rather than method that will likely work.]

Wednesday, June 2, 2010

The Lantern and the Bridge

A small family is being pursued by an unknown enemy in the middle of a dark, dark night.  It comes to a deep chasm spanned by a narrow bridge. 

The family is composed of a father, mother, grandfather, and child.  The father is athletic and can cross the bridge in 1 minute; the mother can cross in 2 minutes; the child can cross in 5 minutes; and the grandfather, the slowest, takes 10 minutes to cross.  They have a lantern with them. 

Since it's pitch dark, the bridge can't be crossed without the lantern.  The bridge is so narrow that only two can cross at a time, and each pair can only move as quickly as its slowest member. 

Their pursuer is likely not far behind.  What is the quickest way to get everyone across the bridge?