Advertising states that, for a certain lottery ticket, "every
fifth ticket carries a prize". If you buy eight tickets, what
is...
(a) the probability that you get at least one winning ticket
among the eight?
(b) the probability that you get exactly one winning ticket? If,
instead of deciding in advance how many tickets to buy, you
continue buying tickets until you have a winning ticket...
(c) what's the name of the probability distribution of the
number of tickets you buy ? If you continue buying tickets until
you have two winning tickets...
(d) what's the name of the probability distribution of the
number of tickets you buy ?