In a class of five students, P, Q, R, S, and T, P is taller than Q but shorter than R. S is shorter than T but taller than Q. Who is the tallest among them?

B. R

Among five students, Alice is older than Bob but younger than Carol. David is younger than Bob, and Eva is older than Alice. Who is the youngest?

C. DAVID

D is the daughter of E. F is the son of E. How is F related to D?

A. BROTHER

If '?' represents division, '?' represents addition, and '?' represents subtraction, what is the value of 20 ? 4 ? 6 ? 2?

C. 12

K is the grandmother of L. M is the father of L. How is M related to K?

C. SON-IN-LAW