I'm trying to understand when I can use the binomial distribution. I have searched some examples online and I'm wondering if I can use them in this situation:
if we had a deck of 20 cards and we choose a hand of four cards and recorded the number on aces, i.e. the number of aces in a hand of four cards - I think no, because the probability of success varies depending on the hand - is this a valid reason?
The number of throws of a fair coin until the first head is obtained
I also think no here because I'm not sure how to define "n" here - could someone explain this one to me?