In the series A, C, E, G, I, what is the 4th letter?

A. G

In the sequence X, Y, Z, A, B, C, what is the 3rd letter?

A. Z

If A is the brother of B, and B is the sister of C, how is A related to C?

A. BROTHER

If A is the brother of B, and B is the sister of C, what is the relationship of A to C?

A. BROTHER

If M is the father of N, and N is the son of O, what is the relationship of M to O?

B. FATHER-IN-LAW