1. D: The overlap of the two sets represents the intersection, which is the set of elements common to both sets <em>M</em> and <em>C</em>. In this case, it's the set {4, 5, 6}.
2. D: <em>P</em> is the set of the first 100 multiples of 8 (8*1 = 8, 8*2 = 16, and so on)
3. C: <em>n</em>(<em>A</em>) represents the number of elements in the set <em>A</em>. When

that means the sets <em>A</em> and <em>B</em> are disjoint, represented by the two circles with no overlap.
4. E:
is the set of elements belonging to either set <em>A</em> or <em>B</em>. The three elements of <em>A</em> are all in <em>B</em>, so <em>A</em> is a subset of <em>B</em>. This means
.
Because <em>A</em> is a subset of <em>B</em>, we have
.
is the complement of
, which refers to the set of elements *not* belong to
. These are all the numbers in <em>U</em> that are not in this union, which would be
.
Because we know
, we have
.