Decide whether the following sets have the same cardinality or not.

a)Z+ and {x | x is a positive real number} b)Z and {10, 20, 30, 40, 50 . . . . } c){1, 3, 5, 7, 9 . . . . } and { . . . . -6, -4, -2, 0, 2, 4, 6 . . . . }