In a very large apartment building in New York 75% of residents have a pet. In that same apartment building 30% are over the age of 65 years. It is also the case that 23% of the residents have a pet and are over the age of 65 years.

A. You sample three people at random from this apartment house. What is the probability all of them have a pet?

Show the work/expressions that lead to the answer.

B You sample two people randomly. What is the probability that either both are over 65 years of age or both are not over the age of 65? Show the work/expressions that lead to the answer. I don't need the intermediary arithmetic calculations. Write the probability to four decimal places.

C You sample seven people randomly. What is the probability that at least one person is not over the age of 65 years? Show work. Write the probability to four decimal places.