One of my colleagues was asked the following brain teaser or puzzle during an interview at Goldman Sachs & Co.:

You have two identical breakable objects, such as glass pebbles. You are standing in front of a 100-story building and you are told that staring at certain floor, the objects start breaking as you drop them off the balcony. What is the optimal (i.e. minimum number of tries) solution to find out which floor the objects start breaking at?

For example, you can take the approach of binary search. Drop the object down from the 50th floor. If it breaks, you will have to start from the second floor and if the floor you are looking for is truly the 50th, you will have to try 48 more times, totaling in 49 tries. If the object didn’t break, you can try the 75th floor, etc. This, however, is not the optimal solution.

I asked my friend, Radu Gabudean, to solve the question. He told me that I had asked him the same question a year ago and that he had already told me the solution. I challenged him by saying that I wasn’t sure what he was talking about and if he wanted me to take him seriously at all, he should prove it. Two hours later, he sent me the solution and the proof. Don’t mess with the finance PhDs!

In my previous post I mentioned an article in Stanford Report on psychological effects of stress.  Greate quote from the article:

Typically, observant Mormons and other religious people are less likely to smoke and drink, he noted. “But once you control for that, religiosity in and of itself is good for your health in some ways, although less than some of its advocates would have you believe,” Sapolsky said. “It infuriates me, because I’m an atheist, so it makes me absolutely crazy, but it makes perfect sense. If you have come up with a system that not only tells you why things are but is capped off with certain knowledge that some thing or things respond preferentially to you, you’re filling a whole lot of pieces there-gaining some predictability, attribution, social support and control over the scariest realms of our lives.”

By the way, I couldn’t agree more, but at the same time this is quite depressing.  As the trite goes: “Ignorance is a bliss”.

I stumbled upon some interesting statistics. It’s not reading for a rainy day, but it has some interesting and perhaps surprising facts if you look closer.  The total suicide ratest, per 100,000 citizens, of the countries that WHO had information on:

http://www.who.int/mental_health/prevention/suicide/suiciderates/en/print.html. 

It should be no surpise that 16 out of the top 25 countries on the list are either Eastern European countries or countries associated with the former Soviet block.  However, what struck me as interesting was that Japan, Belgium, Switzerland, France, and Luxemburg made the top 20!  Here are is the sorted result of the top 25:

On that note, there was a great article in Stanford Report about psychological effects of stress.  Although, I wasn’t impressed by Robert Sapolsky’s insight on how stress levels are high among the Americans and the Japenese, but that the Japenese seem to handle stress better, since life expectancy is high and they have “extremely supportive social network”.  How does that make sense if 5 out of every 10,000 people in Japan commit suicide!?

So you are wondering what universities should you send your kids to?  There is an interesting Wiki entry out there that lists references from Newsweek, Webometrics, Shanghai Jiaotong University, and The Times including the schools that you should consider. Update: Some of the links may not work anymore, but the general consensus seems to be: 1. Harvard, 2. Cambridge, 3. Stanford, 4. Berkeley, 5. MIT or 1. Harvard, 2. MIT, 3. Cambridge, 4. Oxford, 5. Stanford.

Steve Job’s 2005 Stanford commencement address has been already widely distributed on the internet, I’m sure, but in case you have not read it, you should!  In addition to being a great story about the life of a successful business man, it is also a great lesson for many who dream big. The full text was published by Stanford Report.

This is my second attempt to keep an online weblog.  I am hoping to be more persistent this time around and include more material about my interests.  Please feel free to post comments and send me suggestions–this will help me further to keep the weblog going.  Thank you and enjoy!

Note: The title “Hello World!” has its origins in the computer programming world, for those who did not know about it.  A computer program that prints out the two words usually demonstrates the simplest form of a computer program.  You can read about it more on Wiki.