In a coded relation, if M + N means M is the daughter of N, M - N means M is the son of N, and M × N means M is the grandfather of N, what is the relationship of O if M + O - N?
If A + B means A is the brother of B, A - B means A is the sister of B, and A × B means A is the father of B, what is the relationship of C if A + C - B?
In a coded relation, if P × Q means P is the mother of Q, P ÷ Q means P is the son of Q, and P + Q means P is the sister of Q, what is the relationship of R if P × R ÷ Q means P is the mother of R and R is the son of Q?