Problem $1-(8$ marks$=4+4)$Dominic$,$ an original Italian barber is located in NDG$.$ An old customer mentions that he has felt the waiting time to be $30$ minutes on average according to his longstanding experience. Also Dominic himself believes that, on average customers show up every $7\mathrm{.}5$ minutes. He already has $5$ seats in his place.a$)$ Dominic wants to know whether the number of seats in his barber shop would be good enough on average.