Probability question

If 1 in 100 people wear glasses, then what is the probability that I, who is in a group of 5000 people, wears glasses?

I'm not trolling. I'm just a bit surprised at how confused people are when it comes to probabilities.

You're really confusing a stochastic (in this case Bernoulli) *process* with the probability of a simple *event*. The probability of someone wearing glasses in a group of N people, n of whom do wear glasses is just p=n/N (and hence certainly cannot be 1/100 when N=10).

Now if you consider the experiment of picking a person at random (i.e. uniformly) from the lot and checking whether she wears glasses, it's a Bernoulli process of parameter p (which again cannot be 1/100 when N=10, that's something I *do* know). You can indeed compute the probability of getting k successes (i.e. people wearing glasses) after N iterations of that process, but that's pretty irrelevant to the whole problem.