A specific location has a 10% chance of rain on any given day. What is the probability that it will take a week for it to rain on two separate days? Here. the answer is 0.0354294.

1. Why did we use negative binomial distribution here instead of geometric or binomial distribution?
2. Convert the above question into 2 types so that it would require to use geometric/binomial, one type for geometric distribution and the other type for binomial distribution