Let A = {15, 25, 35, 45, 55, 65} and B = {25, 45, 65}. What is A ∩ B? can someone please help me

Question

kmeis002 · Answer

By defintion, the intersect operator only returns the elements that are SHARED by each element, so
$$ A \cap B $$
is asking, what elements does each set share.

$$ A \cap B = {25, 45, 65}$$

Even though it did return all the elements in B, this is because B is a proper subset of A. Another example that may help illuminate:

A = {10, 15, 16, 21}  and B = {5, 10, 16, 11, 18}

Then

$$ A \cap B = {10, 16}$$

kmeis002 · Answer

*shared by each set

anonymous · Answer

a. {15, 35, 55}
b. {25, 45, 65}
c. {15, 25, 35, 45}
d. {15, 25, 35, 45, 55, 65} 
is the answer b

kmeis002 · Answer

Correct, sorry for the missing brackets, I forgot to insert them as a symbol for the latex command :(

anonymous · Answer

so do you think its C?

kmeis002 · Answer

No, the answer is B, since 25, 45, and 65 are shared by each set.