Letters coded as digits; decode from given coded words/sums

CAT has tested this idea 8 times across 2 papers, from 2018 to 2019. Solve one, and the others are the same method with different numbers or wording, which is why repeated concepts are the most efficient thing to practise.

Question	What it asks	Answer
CAT 2019 Slot 1 · DILR Q25	Six-digit addition with letters for distinct digits	1
CAT 2019 Slot 1 · DILR Q26	Six-digit addition with letters for distinct digits	9
CAT 2019 Slot 1 · DILR Q27	Six-digit addition with letters for distinct digits	7
CAT 2019 Slot 1 · DILR Q28	Six-digit addition with letters for distinct digits	6
CAT 2018 Slot 2 · DILR Q25	Words coded as sorted digit strings, digits share letters	D
CAT 2018 Slot 2 · DILR Q26	Words coded as sorted digit strings, digits share letters	D
CAT 2018 Slot 2 · DILR Q27	Words coded as sorted digit strings, digits share letters	A
CAT 2018 Slot 2 · DILR Q28	Words coded as sorted digit strings, digits share letters	A

Part of Quant-based Puzzles (127 questions since 2017).