Then answer provided by the website is 4,5,6,7,8, but believe 1,2,3 can also be answers because - what if A = {3,3,3,3} and B = {1,1,3,3}
or
A = {3,3,3,3}
B = {3,3,3,3}
or
A= {1,2,3,3}
B= {1,2,2,3}
In the above cases, the number of elements in the union set are 2,1, and 3 respectively.
The reason to have thought of 1,2, and 3 as possibilities is because the question never mentioned distinct elements/unique elements. It was just “elements”. Am I wrong for thinking in this way? Because I’ve had plenty of questions where I fumbled because I didn’t think of something being negative/0/equal and so on.
Any help will be appreciated!