Answer
a) yes
b) no
c) yes
Work Step by Step
a) The first set in the pair is an empty set. An empty set is a subset of every set.
b) The first set in the pair contains 5 as one of its members. 5 is not a member of the second set in the pair, so the first set is not a subset of the second set.
c) 3 is the only member of the first set. 3 is also a member of the second set. Since every member of the first set is also a member of the second set, the first set is a subset of the second.