They end up with assemblies or parliaments of that size because, the argument goes, the cube root of the population is the optimal size.

BBC: Incongruous, inconsistent, irrational

One theory goes like this: that most countries have ended up with first house sizes that correspond to the cube root of their populations.

BBC: Incongruous, inconsistent, irrational

What's the cube root of 3 million?

BBC: Incongruous, inconsistent, irrational