A family consists of a mother, a father, and their three children: P, Q, and R. The mother is a nurse, the father is an engineer, and P is a student. If Q is older than P and R is younger than P, what can be inferred about R's age compared to Q?
In a family, there are four members: W, X, Y, and Z. W is the grandmother of Y, X is the father of Y, and Z is the sister of Y. What is the relationship between W and Z?