# Category Riddle of the day

## Zarankiewicz’s Problem

Zarankiewicz’s problem plays an important role in extremal combinatorics. Let’s first learn few things about Kazimierz Zarankiewicz from Wikipedia. Unfortunately, his life had a lot of suffering. He had to live the nightmare of concentration camps during World War II and he was a revolutionary. He was not a guerrilla but continued to teach despite the Nazi […]

## Humans and Randomness

To be honest, this is an experiment I had though of as being an interesting one but never went into the trouble of doing. Dan Meyer however made it happen and thanks to him we can see that a human despite its good effort to imitate a coin cannot do that well. Why though? Subconscious? For […]

## Geometric mean

Here is my riddle of the day for you. Explain why the following piece of Matlab code returns the following >>blog1(10,3) x=5.477226, y=5.477226 sqrt(x0y0)=5.477226 Here is the piece of code: %lasting gemsfunction function blog1(x0,y0) x=x0; y=y0; for i = 1 : 100000 tmp=x; x = (x+y)/2; y = 2*tmp*y/(tmp+y); end fprintf(‘x=%f, y=%f\n’,x,y); fprintf(‘sqrt(x0y0)=%f\n’,sqrt(x0*y0)); Also, generalize […]