Universal set U=x:x5−6x4+11x3−6x2=0, A=x:x2−5x+6=0 and B=x:x2−3x+2=0 then the number of elements in (A∩B)′ is equal to
U=x:x5−6x4+11x3−6x2=0={0,1,2,3}A=x:x2−5x+6=0={2,3} and B=x:x2−3x+2=0={2,1}∴(A∩B)′=U−(A∩B)={0,1,2,3}−{2}={0,1,3}