Sun is to Day as Moon is to ?

A. NIGHT

If P ÷ Q means P is the father of Q, and Q - R means Q is the sister of R, what is the relationship between P and R?

B. UNCLE

What character should replace the question mark in the sequence 3, 6, 9, ?, 15?

B. 12

Teacher is to School as Doctor is to ?

A. HOSPITAL

If M + N means M is the sister of N, and N * O means N is the mother of O, what is the relationship between M and O?

B. AUNT