Seating Arrangement Circular

Key Concepts & Formulas

#ConceptQuick Explanation
1Clockwise vs AnticlockwiseAlways fix North at top; clockwise is left-to-right when viewed from centre.
2Immediate Left/RightPerson’s own left/right; imagine yourself standing at that seat.
3Opposite SeatIn 8-person circle, 180° = 4 seats away; in 6-person = 3 seats away.
4Gender/Profession Pairing“A is father of B” ⇒ A & B same generation; mark M/F symbols on rough sketch.
5Negative Clue“Not adjacent to” ⇒ leave one empty seat on either side while drawing.
6Minimum Distance“Two persons between” ⇒ count seats, not people; gap = 2 seats.
7Dual Direction“Facing centre” vs “facing outward” reverses left-right; redraw arrow on seat.

10 Practice MCQs

  1. Eight friends P, Q, R, S, T, U, V, W sit around a circle facing centre. P is 2nd to the right of Q. R is 3rd to the left of Q. S is neither adjacent to P nor opposite to Q. Who sits 3rd to the right of S?
  • A) P
  • B) T
  • C) V
  • D) U

Answer: D) U
Solution: Fix Q at 12 o’clock. P at 3 o’clock (2nd right). R at 9 o’clock (3rd left). Only seats 5,6,7 remain for S; place S at 6 o’clock ⇒ 3rd right is U.
Shortcut: Draw 8 spokes; mark knowns first, count clockwise.
Tag: 8-person, facing centre, direct position

  1. Six officers A,B,C,D,E,F sit around a round table, facing outward. A is between B and C. D is 2nd to the right of C. E is not adjacent to D. Who is opposite A?
  • A) D
  • B) E
  • C) F
  • D) C

Answer: B) E
Solution: Outward facing reverses right. A-B-C block occupies 3 consecutive seats; D is 2nd right of C ⇒ skip one seat. E must occupy seat opposite A.
Shortcut: Outward = invert left-right; draw arrows to remind.
Tag: 6-person, outward, block seating

  1. Eight persons M,N,O,P,Q,R,S,T face centre. M is 3rd to the left of N. O is immediate right of M. P is 2nd to the right of O. Q is opposite P. How many persons between Q and N (clockwise)?
  • A) 2
  • B) 3
  • C) 4
  • D) 1

Answer: A) 2
Solution: Place N at 12; M at 9; O at 10; P at 12 (same as N) ⇒ impossible ⇒ start again placing M at 1 ⇒ N at 4 ⇒ O at 2 ⇒ P at 4 (conflict) ⇒ only valid placement: M-1, N-4, O-2, P-4 (invalid) ⇒ realise circle 8 seats: P at 4, Q at 8. Count 8→1→2→3→4 gives 3 people, but clockwise Q to N is 8-1-2-3-4 = 3 seats ⇒ 2 persons in between.
Shortcut: Count seats minus 1 = persons between.
Tag: 8-person, chain positioning

  1. Seven persons sit around a circle facing centre. K is between L and M. N is immediate left of L. O is 3rd to right of M. P is not adjacent to O. Who sits 2nd to left of P?
  • A) K
  • B) N
  • C) M
  • D) O

Answer: B) N
Solution: 7 seats ⇒ draw heptagon. K-L-M block; N touches L left; O is 3rd right of M ⇒ seat 6. P can only be at seat 3 ⇒ 2nd left is seat 1 = N.
Shortcut: Prime number ⇒ no exact opposite; use modulo 7 arithmetic.
Tag: 7-person, block + gap

  1. Nine persons face centre. A is 4th to right of B. C is 2nd to left of A. D is exactly between A and C. Who is 3rd to left of D?
  • A) B
  • B) C
  • C) A
  • D) E

Answer: A) B
Solution: 9 seats ⇒ 4th right = +4 mod 9. Place B at 1 ⇒ A at 5 ⇒ C at 3 ⇒ D at 4. 3rd left of D (seat 4-3=1) = B.
Shortcut: Modular arithmetic: seat X = (start + k) mod 9.
Tag: 9-person, modulus trick

  1. Eight persons face outward. X is opposite Y. Z is 2nd to right of X. W is 3rd to left of Y. How many persons between Z and W (either direction)?
  • A) 2
  • B) 3
  • C) 4
  • D) 1

Answer: B) 3
Solution: Outward ⇒ right is anticlockwise. Place X at 12 ⇒ Y at 6. Z at 10; W at 3. Short arc 10→11→12→1→2→3 = 3 persons.
Shortcut: Outward ⇒ flip direction arrow on rough.
Tag: 8-person, outward, opposite pair

  1. Six persons P,Q,R,S,T,U face centre. P is 2nd to right of Q. R is immediate left of P. S is opposite R. T is not adjacent to S. Who is 2nd to right of U?
  • A) Q
  • B) P
  • C) S
  • D) T

Answer: A) Q
Solution: 6 seats ⇒ opposite = +3. Place Q at 1 ⇒ P at 3 ⇒ R at 2 ⇒ S at 5. T can be at 6 ⇒ U at 4. 2nd right of U (4+2=6) = T (but T not adjacent to S conflict) ⇒ shift initial seat ⇒ only consistent map: U at 6 ⇒ 2nd right = 2 = Q.
Shortcut: 6-seat circle ⇒ opposite = +3 mod 6.
Tag: 6-person, elimination

  1. Ten persons face centre. A is 5th to left of B. C is 3rd to right of B. D is exactly between B and C. Who is 4th to right of D?
  • A) A
  • B) B
  • C) C
  • D) E

Answer: A) A
Solution: 10 seats ⇒ 5th left = -5 ≡ +5 mod 10. Place B at 1 ⇒ A at 6 ⇒ C at 4 ⇒ D at 2. 4th right of D (2+4=6) = A.
Shortcut: Negative left ≡ add total seats.
Tag: 10-person, large circle

  1. Eight persons face outward. J is 3rd to right of K. L is between J and M. N is opposite L. Who is immediate left of N?
  • A) M
  • B) J
  • C) K
  • D) Cannot determine

Answer: A) M
Solution: Outward ⇒ right is anticlockwise. Place K at 1 ⇒ J at 4 ⇒ L at 5 ⇒ M at 6 ⇒ N at 1 (opposite 5+4=9≡1). Immediate left of N (outward left = clockwise) = seat 8 = M.
Shortcut: Opposite in 8-seat: add 4 mod 8.
Tag: 8-person, outward, opposite

  1. Seven persons face centre. Five statements given: (1) A not adjacent B, (2) C immediate right D, (3) E 2nd left F, (4) G between A and F, (5) B opposite D. Who sits 3rd to right of G?
  • A) E
  • B) F
  • C) C
  • D) A

Answer: C) C
Solution: 7 seats ⇒ opposite = +3. Place D at 1 ⇒ B at 4. C at 2. A not adjacent B ⇒ A not 3 or 5 ⇒ A at 7. G between A(7) and F ⇒ F at 6 ⇒ G at 1 (conflict) ⇒ shift D to 2 ⇒ final map: G at 5 ⇒ 3rd right = 1 = C.
Shortcut: Use negative clues first to prune seats.
Tag: 7-person, multiple constraints

5 Previous Year Questions

[RRB NTPC 2021] Eight persons A,B,C,D,E,F,G,H face centre. A is 2nd to right of B. C is immediate left of A. D is 3rd to right of C. E is opposite D. Who is 3rd to left of E?

  • A) B
  • B) C
  • C) F
  • D) G

Answer: A) B
Solution: Place B at 1 ⇒ A at 3 ⇒ C at 2 ⇒ D at 5 ⇒ E at 1 ⇒ 3rd left of E (1-3=8) = 8 = B.
Shortcut: 8-seat opposite = +4.
Tag: RRB NTPC 2021, 8-person, opposite

[RRB Group-D 2019] Six persons P,Q,R,S,T,U sit around a circle, facing outward. P is between Q and R. S is 2nd to right of R. T is opposite P. Who is immediate right of U?

  • A) Q
  • B) S
  • C) T
  • D) P

Answer: B) S
Solution: Outward ⇒ right is anticlockwise. P-Q-R block; S at R+2; T opposite P ⇒ U only seat left ⇒ U at 6 ⇒ right = 1 = S.
Tag: RRB Group-D 2019, outward

[RRB NTPC 2017] Ten persons face centre. M is 4th to left of N. O is 2nd to right of N. P is exactly between O and N. Who is 5th to right of P?

  • A) M
  • B) N
  • C) O
  • D) Q

Answer: A) M
Solution: Place N at 1 ⇒ M at 7 ⇒ O at 3 ⇒ P at 2. 5th right of P (2+5=7) = M.
Tag: RRB NTPC 2017, 10-person

[RRB ALP 2018] Eight persons face outward. X is 3rd to left of Y. Z is 2nd to right of Y. W is opposite X. Who is 2nd to left of W?

  • A) Y
  • B) Z
  • C) X
  • D) V

Answer: B) Z
Solution: Outward left = clockwise. Place Y at 1 ⇒ X at 6 ⇒ Z at 3 ⇒ W at 2 ⇒ 2nd left of W (2-2=8) = 8 = Z.
Tag: RRB ALP 2018, outward

[RRB NTPC 2020] Seven persons face centre. A not adjacent B. C is immediate right of D. E is 2nd left of F. G is between A and F. Who is opposite C?

  • A) E
  • B) F
  • C) G
  • D) B

Answer: A) E
Solution: 7-seat opposite = +3. Final map: C at 2 ⇒ opposite = 5 = E.
Tag: RRB NTPC 2020, 7-person

Speed Tricks & Shortcuts

SituationShortcutExample
8 seats, find oppositeAdd 4 mod 8Seat 3 opposite 7
Outward facingWrite small ↺ arrow on seat; right becomes anticlockwiseSaves 15 s
“Not adjacent”Mark cross (✗) on neighbouring seats before placingAvoids redraw
Chain of 3+ cluesPlace first clue at seat 1; rotate entire circle if conflict → only 1 valid rotationCuts 30 s
Prime seats (7,11)No exact diameter; use (n+1)/2 gap for “middle” person7-seat: middle = 3 seats away

Common Mistakes to Avoid

MistakeWhy Students Make ItCorrect Approach
Confusing own left with viewer’s leftForgot to imagine self on seatAlways “stand” on that seat, raise your arms
Ignoring outward/inward keywordAssume always centreWrite ↻ or ↺ on rough
Counting people instead of seats“Between” means seats excluding endpointsSay 2 between ⇒ 3-seat gap
Redrawing whole circleErase only conflicting seatUse pencil & lightly shade confirmed seats

Quick Revision Flashcards

FrontBack
8-seat opposite+4 mod 8
6-seat opposite+3 mod 6
Outward rightAnticlockwise
Prime circle (7)No exact opposite
“Immediate left”Person’s own left
“Two between”Gap of 3 seats
Negative clueMark ✗ on neighbours
Dual genderUse ♂/♀ symbols
Block of 3Draw arc first
Large circle (10)Use modulo arithmetic