@thegodfather321 i got it as 8.the qn is total no of elements is 10 and number of elements in x,y,z are equal and x intersection y ,y intersction z and z intersection x are equal.Find the max elements in set X. i gave the value of elements in x and y and z as 7 and x only,y only,z only as 1 each thereby getting a total of 10 and x intersection y ,y intersction z and z intersection x as 7 (equal) and number of elements in x,y,z as 7+1= 8 each.have i missed something?how you got 9 w/o violating the conditions?