Question 1
The complement of set B is all the elements in S but that are not in B, which is
.
We want to find the intersection of set A and the complement of set B, which is the set of all elements that both sets contain.
This is {2, 9, 10, 12}, meaning there are 4 elements.
Question 2
Following a similar logic as the last problem, the complement of set A is
.
Therefore, the desired set is
, and thus there are 6 elements.