Five years is a very long time to wait. Is it correct? My yesterday quiz had this question. I chose "incorrect" but the answer was "correct".

 Yes, It is correct. Remember: - When subjects express a total amount of time -> Singular verbs. ex: Five years is a very long time to wait -> Five years -> a total amount (all five years) - When subjects express a number of individual units -> Plural verbs. ex: Five years have passed since our last match. -> a number of individual units (first year, second year ...)