In a class of students, John, Lisa, Mark, and Sarah are present. John is older than Lisa but younger than Mark. Sarah is the youngest. Who is the oldest?
A box contains red, blue, and green balls. If the selection criteria are to choose only blue or green balls, which of the following selections is valid?
Four friends, A, B, C, and D, are sitting in a row. A is to the left of B but to the right of C. D is not next to C. What is the correct order from left to right?