It is an April Fools' video, nothing to see here.
> ... because the probability of a number has
> three is P(n)=1/10^n and as n->∞ P(n)->0
Er, no. The probability of an n digit number having a three is P(n) = 1 - (9/10)^n, and as n->∞, P(n)->1.I don't understand why you say it's a moot video. The result as stated in the video is complete and correct.