Intersection of 2 sets

 
         
     
    A={2,5,7} 
    B={1,2,5,8} 
     
    HERE the common elements are 2,5 
    Here the   intersection of A,B is shown by overlapping of A,B.  
    

Intersection of 3 sets 
    
    
    Here 
    X={1,2,5,7,8} 
    y={2,3,5,7,9} 
    z={4,5,7,8,9} 
    Here intersection of 3 sets X,Y,Z is Shown by Overlapping of A,B,C.