Distinguish :
Universal set and complement of a set

Distinguish : Null set and universal set

If I is a universal set, then write the complement of the set N.

Taking the set of natural numbers as the universal set, write down the complements of the following sets: { x : x is a prime number }

Taking the set of natural numbers as the universal set, write down the complements of the following sets: { x : x is an even natural number}

Taking the set of natural numbers as the universal set, write down the complements of the following sets: { x : x is a prime number }

Taking the set of natural numbers as the universal set, write down the complements of the following sets: { x : x is an even natural number}