Give an example of three sets A,B,C such that A intersection B is not equal to phi, B intersection C is not equal to phi, A intersection C is not equal to phi and A intersection B intersection C = phi.
A {1,2}
B {2,3}
C {3,1}
now, A intersection B= {2}
B intersection C= {3}
C intersection A = {1}
but A intersection B intersection C= phi