Question

If C = {integers divisible by 2 from 1 to 25} and D = {integers divisible by 6 from 1 to 30}, what is C ∩ D?

{ }
{2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 30}
{6, 12, 18, 24, 30}
{6, 12, 18, 24}

Answer 1

C ∩ D = "set of everything C and D both have in common"

C ∩ D = "integers that are divisible by 2 from 1 to 25 AND integers that are divisible by 6 from 1 to 30"

C ∩ D = {2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24} ∩ {6, 12, 18, 24, 30}

C ∩ D = {6, 12, 18, 24}.