Eight friends D, E, F, G, J, K, L and M are sitting around a circle, all at…
2023
Eight friends D, E, F, G, J, K, L and M are sitting around a circle, all at equal distance, facing towards the center. E is fourth to the right of D, who is right of F. J and M are not sitting together. Two people sit in between D and K. K and F are not neighbours. E is exact right of K. Two persons are in between D and K. L is immediate right of D. G is third to left of M. Who is opposite to F?
- A.
M
- B.
G
- C.
J
- D.
L
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Correct answer: B
Key insight: When people face the centre, their right side is counter-clockwise around the circle.
Use F as a reference at position 0 and count positions clockwise as increasing indices.
From the clues: L is immediately to the right of D, E is fourth to the right of D, and there are two people between D and K. Also E is immediately to the right of K. Interpreting right as counter-clockwise gives K three seats counter-clockwise from D, and E right next to K.
Choose D at position 6 (this satisfies the constraints without loss of generality). Then:
Immediate right of D (counter-clockwise) is L at position 5; E (fourth to right of D) is at position 2; K (two people between D and K) is at position 3; E is immediately right of K as required.
The remaining seats 1, 4 and 7 must be M, G and J. Using 'G is third to left of M' (left = clockwise) places M at 1 and G at 4, leaving J at 7. This also satisfies 'J and M are not sitting together' and 'K and F are not neighbours'.
Thus the seating clockwise from F (position 0) is: F (0), M (1), E (2), K (3), G (4), L (5), D (6), J (7).
The seat opposite F (position 4) is occupied by G, so G is opposite F.