Four friends stand in a line. Dev is immediately behind Asha. Ben is first. Chen is not last. What is the order from first to last?
A little nudge?
Try placing the Asha–Dev pair in each available position.
Ready for the answer?
Ben, Chen, Asha, Dev.
After Ben, the pair could occupy positions 2–3 or 3–4. Positions 2–3 would leave Chen last, which is forbidden. So Asha and Dev occupy 3–4.