In a family, there are three children: X, Y, and Z. X is the son of A and B. Y is the daughter of A and B. Z is the son of C, who is the sister of A. How is Z related to X?
In a family of six members: P, Q, R, S, T, and U, P is the father of Q, Q is the mother of R, S is the sister of T, and U is the brother of R. Who is the grandmother of R?
A, B, C, D, and E are five different fruits. A is sweeter than B but not as sweet as C. D is sourer than E but sweeter than B. Which fruit is the sweetest?