Twenty microprocessor chips are in stock. Three have etching errors that cannot be detected by the naked eye. Five chips are selected and installed in field equipment.
(a) Find the density for X, the number of chips selected that have etching errors.
(b) Find E[X] and Var X.
(c) Find the probability that no chips with etching errors will be selected.
(d) Find the probability that at least one chip with an etching error will be chosen.