Eight people are sitting in two parallel rows, containing four people each, in…
2025
Eight people are sitting in two parallel rows, containing four people each, in such a way that there is equal distance between adjacent persons.
In row 1 – A, B, C and D are seated and all of them are facing south. In row 2 – L, M, N and O are seated and all of them are facing north.
Thus, each person faces another person from the other row. Only two people sit between N and M. D sits to the immediate left of the person facing N. A sits to the immediate right of C. The person facing O sits to the immediate left of D. Who among the following sits to the opposite of D?
Answer: B. L — ConceptIn a two-row facing arrangement the two rows have opposite left–right senses: a person facing north has west on the left and east on the right, while a…
- A.
N
- B.
L
- C.
M
- D.
O
Show answer & explanation
Correct answer: B
Concept
In a two-row facing arrangement the two rows have opposite left–right senses: a person facing north has west on the left and east on the right, while a person facing south has east on the left and west on the right. Persons occupying the same seat number in the two rows form a facing pair, and in a four-seat row the statement that exactly two people sit between two persons forces those two persons onto the two end seats.
Applying it here
Row 1 (A, B, C, D) faces south and row 2 (L, M, N, O) faces north, so row 1 lies to the north of row 2. Number the seats of each row 1 to 4 from west to east; seat i of row 1 faces seat i of row 2.
For a south-facing row-1 person the immediate left is one seat to the east, that is seat number + 1; for a north-facing row-2 person the immediate left is one seat to the west, that is seat number − 1.
Only two people sit between N and M, so in a four-seat row N and M take seats 1 and 4 in some order.
The person facing N is the row-1 occupant of N’s seat number, and D sits immediately to that person’s left, so seat(D) = seat(N) + 1.
The person facing O is the row-1 occupant of O’s seat number, and that person sits immediately to D’s left, so seat(O) = seat(D) + 1 = seat(N) + 2.
If seat(N) = 4 then seat(D) = 5, a seat that does not exist. Hence seat(N) = 1, seat(M) = 4, seat(D) = 2 and seat(O) = 3.
Seat 2 of row 2 is the one row-2 seat still free, so it belongs to L.
A sits to the immediate right of C, and for a south-facing person the right is one seat to the west, so seat(A) = seat(C) − 1. Seat 2 is already taken by D, so the fit among the remaining seats 1, 3 and 4 is seat(C) = 4 and seat(A) = 3, leaving seat(B) = 1.
Seat (west → east) | Row 1 — faces south | Row 2 — faces north |
|---|---|---|
1 | B | N |
2 | D | L |
3 | A | O |
4 | C | M |
Cross-check
L and O are the two people sitting between N at seat 1 and M at seat 4.
B faces N, and the seat immediately to B’s left — one step east — is seat 2, held by D.
A faces O, and A at seat 3 lies immediately to the left of D at seat 2.
C at seat 4 has A at seat 3 immediately to its right.
D occupies seat 2 of row 1, so the person sitting opposite D is the occupant of seat 2 of row 2, namely L.