Formula for finding number of relations is

Number of relations = 2 Number of elements of A × Number of elements of B

 


Where does it come from?

 

We know that

Relation is a subset of Cartesian product A × B

 

Number of relations = Number of subsets of A × B

Using Formula,
Number of subsets  = 2 Number of elements of set

            = 2 Number of elements of A × B

 

Now,

We know that

Number of elements of A × B

   = Number of elements of A × Number of elements of B

 

Thus,

Number of relations = 2 Number of elements of A × B

  = 2 Number of elements of A × Number of elements of B

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.