A, B, C, D and E are sitting on a bench. A is sitting next to B, C is sitting…

In a linear seating puzzle, if two separate clues each place a specific person next to the same target person, and the target does not sit at an end seat, those two people are automatically the target's only two neighbours — no further working is needed to fix that part of the arrangement.

1. The clue “A is sitting next to B” fixes B as one of A's neighbours.

2. The clue “A and C are sitting together” fixes C as A's other neighbour.

3. A cannot be at an end seat, since an end seat has only one neighbour but A already has two named neighbours. So A sits in an interior seat with B on one side and C on the other.

4. To confirm a fully consistent arrangement exists: E is on the left end, so E takes seat 1. C is second from the right (of the 5 seats), so C takes seat 4.

5. Since C is A's neighbour, A takes a seat next to C. A must also sit to the right of both B and E, so A takes seat 3 (immediately left of C) — seat 5 is ruled out because it would leave no seat to A's left for B while keeping B adjacent to A.

6. That places B, A's other named neighbour, at seat 2, leaving seat 5 for D.

7. Final order, left to right: E, B, A, C, D.

Cross-check: C (seat 4) sits next to D (seat 5) — satisfied. D (seat 5) is not adjacent to E (seat 1) — satisfied. Testing the only other seat next to C (seat 5) for A leaves no seat to its left for B, so that alternative fails — confirming seat 3 is the only valid seat for A.

A sits between B and C.