This is mathematical proof, but I guess this is fairly intuitive too..
Line up the series of numbers from 1 to (n-1) once, and in reverse right below that:
    1    +     2 +     3     + ...................+ (n-2)  + (n-1)
(n-1)  + (n-2) +  (n-3) +..................... +   2     +   1
Adding these vertically, these are (n-1) pairs of n.... So the vertical sum is n*(n-1), and since this is twice the sum that we originally wanted.
So, required sum is n*(n-1)/2 or n choose 2.

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That does not really appear to be the case.. I looked for some father-son pairs from Cricket, and I could find both cases..  Here are some cases, where both father and son have same dominant hand:
  • Peter and Shawn Pollock: Both Right handed
  • Vijay and Sanjay Manjerekar: Both Right handed
  • Lala and Mohinder Amarnath: Both Right handed
  • Chris and Stuart Broad: Both Left handed
  • Colin and Chris Cowdrey: Both Right handed
  • Iftikar and Mansur Ali Khan: Both Right handed

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Amit Bhatnagar on on April 8th, 2013

Thanks for the A2A.. This is something that I always thought about when I saw this image, and finally, this question made me do some research..
First, this image is not from India. Not even from any of the other test-playing nations. This image appears to be that of Sultan Qaboos Grand Mosque in Oman:

Even I thought that this may be from some place in India, but after a bit of search, I landed on this blog: Twitter Cricket Sign-In Page, and after closely comparing the architecture of the mosque and the background hills in the two images, I am almost sure that the building in the Twitter homepage image is this mosque in Oman.
Yes, it would have been definitely surprising if Twitter, being a US-based company, used this as their only homepage background. I tried different browsers and tried reloading the homepage multiple times after deleting cookies. As it turns out, this is only one of at least three images that Twitter uses as its homepage background.
Here are the three images that I could find currently being used as Twitter homepage background:


So, Twitter backgrounds have three distinct themes: nature, modern life/city and people (or maybe countryside, first world country, third world country). Any way you look at it, the combination appears more representative of the diverse Twitter population than just a group of young Cricketers!
I think even this combination does not represent Twitter well; I would expect a theme of conversation or human interaction. But perhaps, most of Twitter's frequent users are perpetually logged in to Twitter on their mobile/web, and hence, Twitter does not care too much about the homepage images that are shown to users only before logging-in or after logging out.

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Amit Bhatnagar on on March 14th, 2013
Amit Bhatnagar on on January 23rd, 2013

Sanga sledging Pollock: Sledging in Gentleman style :-)

As an aside, Sanga is a lawyer by education.. You can expect even his sledging to be politically correct! :-)

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Amit Bhatnagar on on January 19th, 2013

Try Duolingo (language tool). You can use it over web, but I feel that the best way is to use the iPhone app.

Definitely unusual, and although it may be too early for me to label it effective  (It's just my third day of learning Spanish using DuoLingo iPhone app; I am loving it so far.), based on the reviews and articles that I have read about this app, this appears to be quite effective. In fact, a recent study found this to be more effective than other traditional methods:
Study: Learning Spanish With Duolingo Can Be More Effective Than College Classes Or Rosetta Stone | TechCrunch

Try it! Certainly, a better use of your free time than Draw Something or Angry Birds (game)

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Amit Bhatnagar on on January 17th, 2013

The concept is called ReTargeting.

Here is a video from AdRoll that can serve as an introduction to this concept:
The concept is not unique to Jabong. In fact, most eCommerce websites these days would deploy some form of retargeting mechanism, either built inhouse, or by using a third party tools like Adroll.

And indeed, as seen in screenshot[1] below, Jabong is using Adroll for this purpose.

[1] The results are from a browser extension called Ghostery. If the website is using a popular third party tool for  web-analytics, tag-management, ad-serving, or A/B testing, Ghostery will detect it.

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Amit Bhatnagar on on January 17th, 2013

There may be a more elegant tool, but you may want to try the good old Site-search on Google..
Syntax: site: <URL of the FB Page> <Search Keyword>

Below is a screenshot of the query that you are interested in:

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Amit Bhatnagar on on December 3rd, 2012

A recent report from eMarketer suggests that number is about 33 Million

Details here:

Personally, I would however recommend you to look at other sources too. eMarketer is usually a reliable source, but I am not fully sure of this study, especially because Twitter is banned in China, and the study lists China as the leading country in number of Active Twitter users.  Some users may be accessing using proxy-services, but still this does not explain the extremely high usage.

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Amit Bhatnagar on on November 28th, 2012

I agree with this!  When it comes to friendship, I have always been a "Quality over Quantity" guy. I have always had a few very close friends, and a lot of acquaintances, and even a guy like me has 800+ friends on Facebook! And that's not a lot: the last I checked, 94 of my friends have 1000 or more friends!

1000 friends! Is it possible for someone to have 1000 real friends! Studies suggest that there is actually a limit to the number of social relationships one can maintain, and for most people, the number is somewhere between  100 and 230 (150 is the commonly used number) ( more about this here: Dunbar's number (

But Dunbar's analysis is from pre-social media days. (His article was first published in 1992) Is it possible that with the advent of social media, the mankind has suddenly become more "social"? Apparently not! Read about this guy's attempts to take on Dunbar, or may be try your own experiment. Either way, I am sure you will come up with similar results!
Dunbar's Number Kicked My Ass in Facebook Friends Experiment | Underwire | (

The cartoon strip below is profound and funny at the same time, and sums up everything I have said above.

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