In the code, if P - Q means P is the father of Q, P + Q means P is the son of Q, and P ÷ Q means P is the sister of Q, what is the relation of R if P - Q ÷ R?
In a coded relation, if A × B means A is the sister of B, A + B means A is the mother of B, and A ÷ B means A is the brother of B, what is the relation of C if A × B + C?