The Gateway to Computer Science Excellence
0 votes

I solved it by taking matrix ,I am confused in commutative 

closed as a duplicate of: GATE1989-1-v
in Set Theory & Algebra by Loyal (5.9k points)
closed by | 60 views
@hemant means aij=aji 1<=I<=n and 1<=I<=n (means rows and columns will be equal because binary relation formed on same sets element ) and whatever we will put in lower half same entries will be there in upper half ,

Thnxx for making it clear :)
But answer to this question is c)they are taking n*n*n*n*.......*n time for diagonal

=N^n so multiply this factor too

@Prince Sindhiya

can you post their solution?


See this


then close your question

1 Answer

+1 vote

Total no of elements = $n^2$

no of diagonal elements = n

so total no of non diagonal elements = $n^2$ - $n$

half of them will be commutative to other half=> ($n^2$ - $n$ $)/$$ 2 $

option b?


by Loyal (6.7k points)

You can also include diagonal elements from set S 

S = { 1,2,3.....N} 

1*1 = 1*1 

2*2 = 2*2 


N*N = N*N


N + (N 2 - N) /2  = N 2 + 1 / 2


Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true
50,737 questions
57,405 answers
105,468 users