Where Grey Matter meets Dark Matter |
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The annual CTP holiday extravaganza (duly delayed as per tradition).
Christmas doth come but once a year. But the first anniversary of founding CTP City only comes once in a lifetime. Amongst some reminiscing we discuss favourite christmas presents and a particularly memorable christmas film.
We have ourselves a merry little quiz.
Cosmic Tidbit - Gauss' addition trick
Legend has a lot of things - and this is one of them: Karl Friedrich Gauss, the greatest of mathematicians, astounded his primary school teacher by correctly adding up the numbers between 1 and 100 in seconds - the answer is 5050. The story goes that precocious little Karl was difficult to teach since he was far ahead of the other kids in his class, and so the teacher gave Karl something to do that should keep him busy for a while. It didn't.
The trick is to notice that 1+100=101, 2+99=101, 3+98=101... So each pair gives 101, and there should be exactly 50 pairs. So 50*101=5050.
In general, you can do the same thing for any even number N using the formula:
(N/2)*(N+1)
There is also an equivalent formula for odd. Feel free to figure it out.