Find the smallest set `A` such that `Auu{1,2}={1,2,3,5,9}dot`

Find the smallest set A such that A uu{1,2}={1,2,3,5,9}

If Xuu{1,2}={1,2,3,5,9}, then :

Find the arithmetic mean of the smallest elements in all triplets of A={1,2,3,4,5,6}.

Write the smallest reflexive relation on set A={1,2,3,4}

Write the smallest reflexive relation on set A = {1, 2, 3, 4, 5}.

Write the smallest equivalence relation on the set A={1,\ 2,\ 3} .

If U={2,3,5,7,9} is the universal set and A={3,7},B={2,5,7,9}, then prove that: (A uu B)'=A'nn B'( ii) (A uu B)'=A'uu B'

If R is the smallest equivalence relation on the set {1, 2, 3, 4} such that {(1,2), (1,3)}sub R , then the number of elements in R is ______