In a certain code language, 'ancient part known' is coded

Solution

I: 'ancient part known' is coded as 'xv nk fn'.
II: 'part tallest records' is coded as 'nd nk pw'.
III: 'living ancient records' is coded as 'gd xv pw'.
From statement I and III, we conclude that 'ancient' is coded as 'xv'.
From statement I and II, we conclude that 'part' is coded as 'nk'.
From statement I alone, we conclude that 'known' is coded as 'fn'.
From statement II and III, we conclude that 'records' is coded as 'pw'.
From statement II alone, we conclude that 'tallest' is coded as 'nd'.
From statement III alone, we conclude that 'living' is coded as 'gd'.
So, the code for 'living known tallest' is 'gd fn nd'.