answer vs solve

answer is a noun but solve is not a noun.

Word	Noun	Adjective	Verb	Adverb
answer	Yes	No	Yes	No
solve	No	No	Yes	No

As verbs, solve is a hypernym of answer; that is, solve is a word with a broader meaning than answer:

answer: give the correct answer or solution to
solve: find the solution to (a problem or question) or understand the meaning of

Other hypernyms of answer include figure out, lick, puzzle out, work, work out.

As verbs, solve is a hypernym of answer; that is, solve is a word with a broader meaning than answer:

answer: understand the meaning of
solve: find the solution to (a problem or question) or understand the meaning of

Other hypernyms of answer include figure out, lick, puzzle out, work, work out.

answer (noun)	solve (noun)
a nonverbal reaction
the speech act of replying to a question
a statement (either spoken or written) that is made to reply to a question or request or criticism or accusation
a statement that solves a problem or explains how to solve the problem
the principal pleading by the defendant in response to plaintiff's complaint; in criminal law it consists of the defendant's plea of `guilty' or `not guilty' (or nolo contendere); in civil law it must contain denials of all allegations in the plaintiff's complaint that the defendant hopes to controvert and it can contain affirmative defenses or counterclaims

answer (verb)	solve (verb)
give the correct answer or solution to	find the solution to (a problem or question) or understand the meaning of
respond to a signal	find the solution
understand the meaning of	settle, as of a debt
react to a stimulus or command
react verbally
give a defence or refutation of (a charge) or in (an argument)
be satisfactory for; meet the requirements of or serve the purpose of
match or correspond
be liable or accountable
be sufficient; be adequate, either in quality or quantity