Question

Let A = {red, yellow} and let B = {1, 2, 3}. Find A X B.
Answer
{red, yellow, 1, 2, 3}
{1, 2, 3}
{(red, 1), (red, 2), (red, 3), (yellow, 1), (yellow, 2), (yellow, 3)}
{ }

Answer 1

AXB means all possible combinations containing one from each set.

Answer 2

so A ?

Answer 3

Sorry, I wasn't clear about it.
The elements of AXB are doublets, containing one from each set, such as (red,1), (red,2), etc. so it should be the third.