A, B, C, D, E, F and G are travelling in a train compartment with a III-tier…

Concept: In an attribute-grid arrangement puzzle (person – profession – berth type), first convert every clue into a numeric constraint on how many people occupy each category, then use those constraints to force placements before assigning the remaining attribute (profession) by elimination. A clue that ties two people's categories together (e.g., "X occupies the same berth type as Y") is best tested by assuming a placement and checking that it does not overflow the fixed seat counts.

Step-by-step application:

1. There are 7 berths in total (2 lower + 3 middle + 2 upper) for the 7 people, and 7 distinct professions to match to them.

2. A is the Engineer and is not on the upper berth. The Architect is the only other person sharing A's berth type, so A's berth type has exactly two occupants — that must be Lower or Upper (the two berth types with a count of 2); since A is not on the Upper berth, A is on the Lower berth, and the Architect is the second Lower occupant.

3. B and F are not on the middle berth. Since the two Lower seats are already taken (by A and the Architect), B and F must both be on the Upper berth — filling it completely with B (Pathologist) and F (Lawyer).

4. C, D, E and G remain. One of them must be the Architect sharing the Lower berth with A, and the other three fill the three Middle berths. C is the Pharmacist, and G is explicitly not the Architect, so the Architect is either D or E.

5. Testing E as the Architect fails: E would then be on the Lower berth, and the clue that E occupies the same berth type as the Doctor would force the Doctor onto the Lower berth too — but the two Lower seats are already taken by the Engineer (A) and the Architect (E), leaving no room for a distinct Doctor. So E cannot be the Architect.

6. Therefore D is the Architect, occupying the Lower berth together with A.

7. C, E and G fill the three Middle berths. The Pharmacist is already fixed to C; since G is not the Journalist, G must be the Doctor, leaving E as the Journalist — and E (Middle) does share a berth type with the Doctor, G (Middle), confirming that clue.

Cross-check: Every clue is satisfied by this grid: two Lower (A-Engineer, D-Architect), three Middle (C-Pharmacist, E-Journalist, G-Doctor), two Upper (B-Pathologist, F-Lawyer); all seven professions are used exactly once, and each of the six original clues holds true against this table.

Result: The pair occupying the lower berth is A and D.