  We show that the mass function method makes it much easier to obtain the
exact solutions of Einstein equations. The known solutions for empty space and
for the universe filled with dust-like matter are considered from the point of
view of the method and new exact solutions are obtained. Generalized solutions
for the Schwarzschild type black holes are considered. It is shown that such
black holes always contain non-baryonic matter. New exact solution for the
black hole embedded into dust matter cosmological background is obtained.
