Question

Is it Exponential distribution? or Geometric distribution?

Answer 1

I believe you use the exponential distribution to find the probability of success (say "p"). Then, you use the Geometric(p) distribution using the "p" you calculated from the exponential as your success probability. Also, in b), you use a negative binomial (which is really just a generalized geometric distribution).

Part c) Find the probability to 2 decimal places that the first success occurs in an odd-numbered observation. That is, the first success occurs in the 1st or 3rd or 5th or 7th (and so on) observation.