Four friends, A, B, C, and D, attended a seminar on different days. A attended on Monday, B attended on Wednesday, and C attended the day before D. What day did D attend?
In a family of six members A, B, C, D, E, and F, A is the father of B. C is the mother of B. D is the sister of B. E is the brother of B. F is the grandfather of B. Who is the grandmother of B?