Is it necessary to reply to a solution email by a thank-you email?

If I asked via email someone, say a member of the graduate admission staff of a school I am applying to, some question, and if the staff member replied to my email with a solution to my problem, does the staff member expect to receive a thank-you email from me?

At the present stage I still am not good at evaluating if it is suitable to reply to such an email by a thank-you note.