Question

No of Symmetric relations containg set with A={1,2,3,4,5,6,7} which contain exactly four ordered pairs.

Comments

Relation is nothing but ordered pairs. so we can represent how many ordered pairs from n elements --> n² right.

So matrix is : 

(1,1) (1,2) (1,3) (1,4) (1,5) (1,6) (1,7)

(2,1) (2,2) (2,3) (2,4) (2,5) (2,6) (2,7)

(3,1) (3,2) (3,3) (3,4) (3,5) (3,6) (3,7)

(4,1) (4,2) (4,3) (4,4) (4,5) (4,6) (4,7)

(5,1) (5,2) (5,3) (5,4) (5,5) (5,6) (5,7)

(6,1) (6,2) (6,3) (6,4) (6,5) (6,6) (6,7)

(7,1) (7,2) (7,3) (7,4) (7,5) (7,6) (7,7)

bold ones are diagonal elems.

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thank u bro,good explanation

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welcome bro :)