Is it exponential distribution? or geometric distribution?
the life times, y in years of low-grade lightbulbs follow an exponential distribution with a mean of 0.7 years. a tester makes random observations of the life times of this lightbulbs and records them one by one as either a success if the life time exceeds 1 year, or as a failure otherwise.

part a)find the probability that the first success occurs in the fifth observation.

part b) find the probability of the second success occurring in the 8th observation given that the first success occurred in the 3rd observation.

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.