Question

If A = {1, 2, 3, 4, 5, 6, 7, 8, 9} and B = {3, 6, 9, 12, 15, 18}, what is A union B?

{3, 6, 9}

{1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 15, 18}

{1, 2, 3, 3, 4, 5, 6, 6, 7, 8, 9, 9, 12, 15, 18}

{ }

Answer 1

i think its { }

Answer 2

Union means "all"

{1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 15, 18}

But don't repeat the same numbers.