So I started studying probability and while it seemed all ok I'm having trouble wrapping my head around this one. So the question is: We have 100 balls , 10 black and 90 white. In 50 tries what is the probability of getting 0 to 10 black balls? Now I need to get probability for excels BINOM.DIST function and am having dilemma. Do we need to calculate 1 black divided by total black (10) or getting 10 black out of 100 total? I get 0.1 for both cases and that makes this bit more confusing.
Draws with replacement
Assuming you mean draws with replacement by tries:
To help you clarify the question: Is the probability in the binomial distribution the probability of a success or is the probability of drawing a particular ball given a success?
Draws without replacement
If you are looking for a distribution and draws without replacement. (ie what is the probability of drawing 0,1,2,3...?) then you should consider:
How many different states/draws there are where you take 50 from 100 balls? How many of the 10 black balls would you draw? How many of the white balls would you draw? How can you combine these into a probability?