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 = R + Q mean ?

Answer: B. P is the daughter of Q.

P = R + Q means P is the sister of R who is the son of Q i.e. P is the daughter of Q.
So, the answer is (b).