A family consists of four members: P, Q, R, and S. P is the father of Q, Q is the sister of R, and S is the mother of R. Who is the father of R?

A. P

In a family, there are three children: X, Y, and Z. X is the brother of Y, and Y is the sister of Z. What is the relationship between X and Z?

C. BROTHER

Key is to Lock as Password is to ?

A. ACCESS

In a race of 50 runners, if Mark is 15th from the top, what is his position from the bottom?

A. 36TH

What letter comes next in the series: A, C, E, G, ?

A. I