Keith McGuigan posted a great puzzle on his blog. I liked it so much had to add it to my collection. If you enjoy logic puzzles, be sure to visit Keith's blog, as he will be posting new challenges now and then. Like the "3 bulb" puzzle I posted earlier, there is a "key" approach that unlocks this problem that you'll find useful in attacking other puzzles. Good luck!

Five greedy pirates follow a treasure map to a deserted island. They dig at the "X", and uncover 100 gold coins! The pirates are unionized and therefore seniority rules. However, they are also democratic, and the majority has veto and execute (as in: "off with his head") power... so the leader (the most senior pirate) must be careful.

The leader gets to decide how to divide up the booty amongst himself and the rest of the pirates. However, after the plan is presented, all the pirates (including the leader) votes on the plan. If less than 50% approve the plan, the leader is fed to the fish and the process repeats itself with the next most senior pirate.

Now, the pirates are all pretty smart and don't make rash or emotional decisions. All of the pirates use the following priorities (in the following order) to drive their voting:

1. They don't want to get killed
2. They want to get the most money possible
3. They want to kill other pirates

So, how does the leader divide up the treasure such that he keeps as much as he possibly can for himself, and still survivie?

If you give up, here is the solution:
<check back soon>

February 25, 2005 03:18 PM EST Permalink

This one requires some out-of-the-box thinking, but still, there is no "trick". Solving this one will give you insight into an approach for a large "class" of logic puzzles - questioning assumptions and using residual data. Good luck.

You have three light switches by the front door downstairs. These are tied to three bulbs down in the basement. You have no clue which switch controls which bulb. You can't see the bulbs from the front door. Thankfully, you do know that toggling each switch "up" turns one of the three bulb.

You are lazy, or maybe just self-challenging. Regardless of your motivation, you think there has got to be a way to figure out which switch controls which bulb with a single trip to the basement.

Again, there aren't any cute tricks... You can't count on the switches being ordered similar to the bulbs. You can't see or access the wires. You have no helpers or remote cameras or anything like that.

But, taking one trip down to the basement (while you're still down there) you can tell which switches control which bulbs! How?

If you give up, here is the solution:
http://blogs.sun.com/roller/resources/dcb/SOLUTION_3_Bulbs.html

February 25, 2005 01:23 PM EST Permalink