>2. Google, for not being able to, "prove a random number is truly random," This definitely does not seem like a question that should be in a coding interview.

>2. Google, for not being able to, "prove a random number is truly random," This definitely does not seem like a question that should be in a coding interview. However, this is an answerable question under certain assumptions. It's possible to make a source of randomness more entropic. (c.f. https://en.wikipedia.org/wiki/Randomness_extractor https://en.wikipedia.org/wiki/Randomness_extractor) What we can do is slice up the number into a given length and estimate the H_{\infty} entropic measure among our sliced-up numbers, treating the numbers as samples from some random source. edit: if for example you're a crypto researcher, then this question seems warranted.