Brainteasers

By Julianne Scibetta, University of the Sciences in Philadelphia

A friend of mine recently passed along a "Pirate Problem" from his alma mater. Since it's a doozy, there's just one question this month.

The Pirate Problem

Five pirates, who are perfect logicians, have three priorities in the following order:
1. Staying alive.
2. Obtaining as much gold as possible.
3. Killing other pirates.
In other words, these pirates will do whatever it takes to stay alive. After that priority is met, every pirate will choose gold over killing.
The five pirates come upon a treasure chest of 100 gold coins. They agree that they each will draw straws to determine order, first through fifth, and then each pirate in turn, starting with the one with the shortest straw, will suggest how to split the gold coins. All (living) pirates will vote on the proposal. If a proposal fails to receive a majority vote (more than 50%), the pirate making the proposal is killed, and the next pirate makes his proposal. Consider the order of the pirates to be A, B, C, D, and E. Which pirate's proposal will be the one accepted? What is the proposal? Explain the logic.

Send your answers to Julianne Scibetta at jscibetta3@hotmail.com, and look for the results in the next LCN issue! Please also share any great brainteasers you love to give to friends (or students!) and I'd be more than happy to include it in the next list.

Answers from last issue's brainteasers:

Everyone was spot-on for entries for last issue's summer vacation brainteasers! Congratulations to Tara Sullivan of Red Lake College, IL and Matthew Winkler of Rutgers University, NJ for their perfect scores! Honorable mention goes to Janet Elder of Richland College, TX.

The Pirate Problem, from Siena News, Winter 2005.