Question

If we take Set A = {1,2}, Set B = {3,4} and Set C ={{}}. Then what is the Uniiversal Set of Set A, Set B and Set C ?​

Answer 1

Answer:

The universal set is is {{},1,2,3,4}

Answer 2

Answer:

Universal set is a set which contains all elements and of which other sets are subsets.

It means that A⊂U, B⊂U and C⊂U.

Then U can be { 1 , 2 , 3 , 4, ... }

But it's not important that U should contain elements of A, B and C only.

U can be { 1 , 2 , 3 , 4 , 5 , 6  }

U can be { 1 , 2 , 3 , 4 , 5 , a , b , c , d , e }

U can be { √5 , √3, a , 1 , z , 2 , 3 p, r , 4 }

U can be any set but the only condition is that it should contain elements of A, B and C

∴ U should atleast contain 1,2,3,4 (phi { } is in every set)  

But U can contain infinite number of other elements also.