A recruiter at a company is attending a university's career fair. He has decided to send an email asking for newer employees to volunteer and talk about their job experience and work-life balance at the company with students attending the career fair. The recruiter sends the email to 15 newer employees. Suppose that the time it takes each of the employees to respond is an independent exponential random variable with a mean 45 minutes. The recruiter will stop checking emails after he gets 5 responses, and he constantly monitors his email until he gets those 5 responses. If T is the amount of time the recruiter is monitoring his emails, (a) (10 points) Find E[T ]. (b) (10 points) Find V ar(T )