掲示板 Forums - Difference between 返事, 返信, 回答

From my limited understanding (which may be incorrect) is:

返事 - is a generic reply or response (kanji gives us *reply* *thingy*)

返信- is a more formatted response, so for things like reply to e-mails or letter (kanji gives us a *faithful* *reply*)

回答 - is for a answer to something where there isn't a correct answer, like a survey (kanji gives us *going around about* an *answer*)

From my limited understanding (which may be incorrect), that sounds about right

For a test question where there is only one "solution" like a math question e.g. 2+5= ?, I think that 解答 is used. (kanji gives us *unraveled* *answer*)