what is the proper defination of UNIVERSAL SET - Maths - Sets

Question

what is the proper defination of UNIVERSAL SET ?

Lalit Mehra · Accepted Answer

Hi!
Here is the answer to your question
A set that contains all sets in a given context is
called the universal set It is the super set of each of
the given sets It is generally denoted by
U
Example:
1 If A = {1, 2, 3}, B = {2, 3,
5, 6} and C = {1, 3, 6, 7}, then U =
{1, 2, 3, 4, 5, 6, 7} can be taken as the universal set because
each of the sets A, B and C is a subset of
U or U is the super
set of the given sets A, B and C
2 The set R of all real numbers can be
taken as the universal set for the set of natural number
(N), set of integer (Z), set of rational number and
set of irrational numbers
Cheers!