Eight colleagues H, I, J, K, L, M, N, and O are sitting surrounding an octagon…

Concept: In a circular/polygon seating puzzle where everyone faces the centre, a person's own left hand points in the clockwise direction (as seen from above), so "second to the left of X" means two seats clockwise from X. When the table has an even number of seats, the seat "in front of" (directly opposite) a person is exactly half the total seats away — on an 8-seat octagon, that is 4 seats along the arrangement.

Applying this to the arrangement:

1. “J is immediate to M” and “L is between J and H” chain four seats together: H - L - J - M, in that order.

2. “I is the neighbour of both M and N” places I between M and N, extending the chain to six consecutive seats: H - L - J - M - I - N.

3. Number these six seats 1 to 6 clockwise: H = 1, L = 2, J = 3, M = 4, I = 5, N = 6.

4. “H is second to the left of K” means K + 2 = H’s seat, so K = 1 − 2 = seat 7 (wrapping around the 8-seat table).

5. “O is second to the left of N” means O = N + 2 = 6 + 2 = seat 8.

6. Seats 7 and 8 exactly fill the two remaining places with no overlap, fixing the full octagon: H(1)-L(2)-J(3)-M(4)-I(5)-N(6)-K(7)-O(8).

7. N sits at seat 6; the seat directly opposite (4 seats away) is 6 + 4 = 10, which wraps to seat 2 — the seat held by L.

Cross-check against every clue:

• H second to the left of K: seat 1 is two seats clockwise from seat 7. Holds.

• I neighbours both M and N: seat 5 sits between seat 4 and seat 6. Holds.

• O second to the left of N: seat 8 is two seats clockwise from seat 6. Holds.

• L between J and H: seat 2 sits between seat 3 and seat 1. Holds.

• J immediate to M: seat 3 and seat 4 are adjacent. Holds.

All five clues are satisfied with all eight seats uniquely placed, so the arrangement is confirmed. The person facing N across the octagon is L.