What a neat mathematical problem is worth? (4,3)
I believe the answer is:
tidy sum
'worth?' is the definition.
The answer and definition can be both quantities as well as being singular nouns.
Maybe there's an association between them I don't understand?
'what a neat mathematical problem' is the wordplay.
'what a neat' becomes 'tidy' (synonyms).
'mathematical problem' becomes 'sum' (I've seen this before).
'tidy'+'sum'='TIDY SUM'
'is' is the link.
Can you help me to learn more?
(Other definitions for tidy sum that I've seen before include "A lot of money" , "Considerable amount" .)