Each test of an integrated circuit (IC) produces an acceptable IC with probability p independent of the test of any other IC. A total of N IC's were tested.
Let X denote the number of accepted circuits.
Let Y be a random variable which is 1 if the last (Nth ) IC was accepted and is zero otherwise (it is a Bernoulli random variable).
(a) Write out the probability mass function (PMF) of X.
(b) Write out the probability mass function (PMF) of Y .