Todays really not my day, I should know this but I'm just too unsure:
Let's say we got a chest with 30 balls in there, 25 black and 5 golden.
I want to find out the probability to get at least 1 golden ball, having 5 tries and not being allowed to put the balls back in there once I get them out.
I do know that its
1 - P(no golden balls in 5 tries)
but I'm having trouble remembering how to get my P
is it 5/30+5/29+...
or maybe 1/30+1/29+...
or even something completely different?
Thanks for your time