If A = {x: x is a natural number}
B = {x: x is an even natural number}
C = {x: x is a prime number}
Then (A ∪ B) ∩ C =
C
A = {1, 2, 3, 4, - - - -}
B = {2, 4, 6, 8, - - - -}
C = {2, 3, 5, 7, 11, 13, - - - -}
A ∪ B = {1, 2, 3, - - - -} ∪ {2, 4, 6, 8, - - - -} = {1, 2, 3, - - - -} = A
(A ∪ B) ∩ C = A ∩ C = {1, 2, 3, - - - -} ∩ {2, 3, 5, 7, - - - -} = C