An infinite sequence of independent trails is to be performed

[TomJerry]

Question :
An infinite sequence of independent trails is to be performed . Each trails resulting in a success with probability p and failure with probability 1-p . What is the probability that
i) atleast 1 success occurs in the first n trails ;
ii) exactly k success occur in the first n trails;
ii) all trails result in a success;
Solution
I am using Binomial distribution.

i) I will find the P(X of getting 0 success)
Then P(X>= 1) = 1 - P(X of getting 0 success) [IS THIS CORRECT]

ii) For the 2nd P(X=k) in binomial [AM I CORRECT]

iii) DOnt know how to do this one

 

[tiny-tim]

Hi TomJerry!

i) yes

ii) yes, but perhaps you'd better write it in full, so we're sure you know what that means?

iii) erm … isn't that just ii) with k = n ?