Question

If C = {2, 3, 4, 5} and D = {numbers divisible by 2 from 1 to 10}, what is C ∩ D?

{2, 4, 6, 8, 10}

{2, 4}

{2, 3, 4, 5, 6, 8, 10}

{ }

Answer 1

What do you think?

Answer 2

on the y-axis
Since D = {2,4,6,8,10}

Answer 3

the third one

Answer 4

well. I see this needs clarification. The intersection of two sets means the elements that are in both of the sets.

Answer 5

So really, we want the numbers from the first set that are also in the second set.

Answer 6

What numbers are those?

Answer 7

it would be the 3rd one

Answer 8

2 is a member of the first set. Is it divisible by 2? Yes.So we will include 2 in our answer.
3 is a member of the first set Is it divisible by 2? No.So we won't include 3 in our answer
4 is a member of the first set Is it divisible by 2? Yes. So we will include 4 in our answer
5 is a member of the first set.Is it divisible by 2? No. So we won't include 5 in our answer.

So what numbers are included in the answer?

Answer 9

It could not be the third answer. 6, 8, and 10 are not in the first set. To be in the intersection, the number must be both in set C and set D.