Q.

Let the sets S={2,4,8,16,…,512} be partitioned into 3 sets A,B,C with equal number of elements such that A∪B∪C=S and A∩B=B∩C=A∩C=ϕ. The maximum number of such possible partitions of S is equal to                [2024]

1 1520  
2 1640  
3 1710  
4 1680  

Ans.

(4)

We have, S={2,4,8,16,…,512}

                      ={21,22,23,24,…,29} so, |S|=9

|A|=|B|=|C| and A∪B∪C=S

and A∩B=B∩C=A∩C=ϕ

Since, |S|=9 so |A|=|B|=|C|=3

So, number of ways of making partition of S=C39×C36×C33

=9!6!3!×6!3!×3!×1

=9!3!×3!×3!=1680