Survive the Russian Roulette...!!!

Back to my favourite game of beating the odds, here is another one....Russian roulette...!!!

Unfortunately you have been captured by the enemy and taken as prisoner of war. Your life now depends on a crazy army colonel who loves to play the game of Russian roulette with his prisoners. If you can survive his game you might get a chance to breathe for few more days. Here is the game...

You have been tied to a chair and won't be able to get up. The colonel brings in a barrel of the gun, six chambers, all empty. He will let you watch him put two bullets into adjacent chambers in the gun. Closes the barrel and spins it for few seconds. He fires one shot in the air, CLICK...the chamber was empty. Now he points it to your head and asks if you prefer to spin the barrel again before pulling the trigger or just pull the trigger without spinning. Which one would you prefer to increase your chances of surviving this deadly game? Remember the gun still has 2 bullets.

File format Bible

If you are a programmer working with different file formats, you would definitely find this site resourceful. I have been crawling the web sniffing math content where considerable portion of scientific material is in non-html/xml format. This site was handy when it came to parsing Microsoft word and powerpoint file format. In case you need a programmatic interface to Microsoft file formats, Jakarta has an answer with their POI project.

MathFind: A Math-Aware search engine

Me and my supervisor Robert Miner submitted a paper on math search engine titled "MathFind: A Math-Aware search engine" to ACM SIGIR 06. It was accepted to be published...!!! The paper talks about our current implementation of a prototype math search engine. We will be presenting it in the forthcoming ACM conference on August 9, 2006 in Seattle, USA.

Is it worth taking risk?

Me and my friend were on vacation in Las Vegas. We both have contradicting personalities. He is a risk taker while I am not. We were playing the Guessing Game in one of the casinos. The game is very simple. There are three boxes say A, B, C where only one of the boxes contains the prize. You need to play all three steps of the game before you claim the prize.

Step 1: You are supposed to guess the box containing the prize. Ofcourse all three boxes are equally probable. Say you chose box A.
Step 2: The game host will then open one of the other two boxes which does not have the prize. That is he wont open the box A as you have already chosen it in step 1. Hence, he will either open box B or C depending on which ever doesnt have the prize. Lets say he opened Box B.
Step 3: In this step, you can either claim the prize from the box A which you chose in first step or you can choose the other unopened box (Box C).

My friend claims, you will always increase your chances of winning if you choose a different box in step 3 rather than trusting your first instinct in step 1. But I argue it doesnt matter as both boxes have equal probability of containing the prize. Do you think taking the risk of switching the boxes increases your chances of winning?

NOTE: There are no tricks in the question. It is purely logical reasoning and the laws of probability.

[HINT: Try to think from the point of view of the game host rather than as a player.]