# Math Help - Poisson random variable

1. ## Poisson random variable

i need help on this questions i really do not understand it

Let X be a Poisson random variable with mean μ and let Y be a
Poisson random variable with mean μ. Assume that X and Y are independent.
(a) Write down the joint probability that X = i and Y = n−i, where n and i
are integers with 0 <i<n
(b) Calculate P(X + Y = n), where n is a non-negative integer.
(c) What distribution does the random variable X + Y have?

2. Originally Posted by sagar
i need help on this questions i really do not understand it

Let X be a Poisson random variable with mean μ and let Y be a
Poisson random variable with mean μ. Assume that X and Y are independent.
(a) Write down the joint probability that X = i and Y = n−i, where n and i
are integers with 0 <i<n
(b) Calculate P(X + Y = n), where n is a non-negative integer.
(c) What distribution does the random variable X + Y have?