Discrete Probability Distribution

[chrisyuen]

Homework Statement

(Answers:
(a) 0.3233
(b) 2
(c)(i) 0.6489
(c)(ii) 0.1669
(c)(iii) 0.2369)

Homework Equations

Formulae for Discrete Probability Distributions

The Attempt at a Solution

I don't know how to solve part (b) only.

For (b), I have no idea.

Is it using the Geometric Progression (a / (1 - r))?

Can anyone tell me how to solve it?

Thank you very much!

 

[CompuChip]

Maybe I am missing something, but doesn't it say that the rainstorms occur independently?
So then wouldn't "there were two storms last year" actually be non-information (i.e. it doesn't change the probability for more than two storms in this year, or any other year)?

(Of course, it would be different if they had said "there has been one rainstorm this year already, what is the probability that there will be more than two")