Find C intersection D.

C: {3, 6, 9, 12, 15, 18}
D: {numbers divisible by 2 from 1 to 20}

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

{6, 12, 18}

{2, 3, 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20}

{ }

I really think its the second one but im so confused.

intersection is just those element that are in both C and D. All you have to do is run down the lists and pick the values that appear in both sets.

C:{3,6,9,12,15,18}
D:{2,4,6,8,10,12,14,16,18,20}

Looks like {6,12,18} are in both sets