All three answers were instantly accepted, despite being very low quality. Two of the questions were from 2016; a third was asked this morning and answered one minute later; the question was incoherent and appeared to be designed to be "answered" in exactly the same way as one of the older two. One of the answers was copied and pasted from a comment on the same question posted by cropredy. (Subsequent to my comment on this answer, the user edited the answer to replace the copy-paste with a link-only answer).
These users appear to be sock puppeting or coordinating with one another in an attempt to boost reputation. What is the best way to address this pattern of behavior? Should I/we simply flag all involved questions and answers?
Edit: additionally, questions asked by "srija" are answered/accepted by "Ramesh M" three times in a single day, January 29.