Five books are arranged on a shelf. Book A is to the left of Book B but to the right of Book C. Book D is to the left of Book E. What is the correct order of the books from left to right?
A family consists of a mother, a father, and three children: P, Q, and R. P is the eldest and is studying medicine. Q is studying engineering and is younger than P but older than R. What is R's field of study?