Find the answer to (5)
I believe the answer is:
solve
'find the answer to' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for solve that I've seen before include "Voles (anag.)" , "Explain (a mystery)" , "Unscramble" , "Deal with (a problem)" , "Unravel (a problem)" .)