function H=hypergeo(N, n, K, k) 
% hypergeo(N, n, K, k)  hypergeometric - keno and lotto problems 
%    N - Total number of choices 
%    n - Number of choices picked as "good" 
%    K - Number of choices you make 
%    k - Number of "good" choices you actually make 
if max(n>N)==1 
   error('n cannot be > N') 
end 
if max(k>K)==1 
   error('k cannot be > K') 
end 
if max(k>n)==1 
   error('k cannot be > n') 
end 
if max(K>N)==1 
   error('K cannot be > N') 
end 
if max((K-k)>(N-n))==1 
   error('K-k cannot be > N-n') 
end 
H=(cmb(n, k).*cmb(N-n, K-k));