A + B means A is the son of B;
A - B means A is the wife of B;
A x B means A is the brother of B;
A ÷ B means A is the mother of B; and
A = B means A is the sister of B.
What does P x R ÷ Q mean ?

Answer: C. P is the uncle of Q.

P x R ÷ Q means P is the brother of R who is the mother of Q i.e. P is the uncle of Q.
So, the answer is (c).