Answer: It's a wrong sentence.
Explanation: Correct sentence should be "Buenas tardes" that means "Good afternoon". Because "tardes" is a feminine and plural noun, so its adjective must match in gender and number: buenas tardes.
It is a way of greeting people for a period from 12:00 p.m. to 6:00 p.m.
[tex]\textit{\textbf{Spymore}}[/tex]