Question

Let Z be a complex number, then Z.Z ¯ is ........ (a) a prime number (b) a non-negative real number (c) a natural number (d) an irrational number
A ………… of an Abelian group is Abelian (a) set (b) subset (c) group (d) subgroup
One of the following is untrue for the description of a non empty set
(a) An element can be written more than once (b) The order in which the elements of the set are listed is not important (c) The roster method is sometimes used to list the elements of a large set (d) Every element must be written exactly once