Important sets in Mathematics  1.  N = Set of all “Natural” numbers. 2.  W = Set of all “Whole” numbers. 3.  Q = Set of all “Rational” numbers. 4.   Z = Set of all “Integers”. 5.  R = Set of all “Real” numbers. 6.  Z +  = Set of “Positive” Integers. 7. Q + = Set of “Positive Rational” numbers. 8.  R +  = Set of “Real” numbers.