If A + B means A is the sister of B, A - B means A is the brother of B, and A × B means A is the mother of B, what is the relationship of C if A + B - C?
If A ÷ B means A is the daughter of B, A + B means A is the brother of B, and A - B means A is the sister of B, what is the relationship of C if A ÷ B + C?