, obvious and 
, leads to confusion when used in
conjunction with central limit theorem (see later).
and 
have binomial distributions with parameters 
and 
respectively.
Here, 
if there are k successes.
Then it is obvious from source of binomial
distribution that 
has a binomial distribution with
parameter 
.
and 
have
Poisson distributions 
and 
.
Then 
has Poisson distribution with
parameter 
.
This is obvious either algebraically, or by using
the result (a) above with 
and
and let 
, 
, fixed 
, 
.