Work out this answer! (5)
I believe the answer is:
guess
I believe this clue is a double definition.
'work out' is the first definition.
(thesaurus)
'this answer' is the second definition.
(thesaurus)
(Other definitions for guess that I've seen before include "Estimate roughly" , "Fancy" , "Speculation" , "Hypothesis" , "Estimate, supposition" .)