Seating

Key Concepts & Formulas

Provide 5-7 essential concepts for Seating:

#ConceptQuick Explanation
1Linear SeatingArrangement in straight line; ends have 1 neighbor, middle have 2
2Circular SeatingArrangement in circle; everyone has 2 neighbors; clockwise/anticlockwise matters
3Facing DirectionNorth/South in linear; Center/Outside in circular; affects left/right positions
4Immediate NeighborsPersons sitting directly next to each other; key for solving constraints
5Position CountingFrom left: 1,2,3…; From right: …3,2,1; Total = Position from left + Position from right - 1
6Row-Column MatrixMultiple rows with fixed seats; person in front/behind relationship
7Vacant SeatEmpty positions; reduce effective neighbors; treat as placeholder

10 Practice MCQs

Generate 10 MCQs with increasing difficulty (Q1-3: Easy, Q4-7: Medium, Q8-10: Hard)

Q1. In a train compartment, 5 passengers are sitting in a row. If the person at extreme right is shifted to extreme left, how many persons are between the original position person and new position person? A) 0 B) 3 C) 4 D) 5

Answer: B) 3

Solution: Original: P1 P2 P3 P4 P5 New: P5 P1 P2 P3 P4 Person P5 moved from position 5 to 1 Between P5’s original and new position: P2, P3, P4 = 3 persons

Shortcut: Total - 2 = 5 - 2 = 3

Concept: Seating - Linear arrangement position change

Q2. Six ticket counters are in a row at Mumbai Central station. If counter 2 is closed for maintenance, how many counters are between the first active counter and last active counter? A) 3 B) 4 C) 5 D) 2

Answer: A) 3

Solution: Active counters: 1, 3, 4, 5, 6 First: 1, Last: 6 Between them: 3, 4, 5 = 3 counters

Shortcut: Count remaining - 2 = 5 - 2 = 3

Concept: Seating - Linear with vacancy

Q3. In a circular railway track, 8 stations are equally spaced. How many stations are between station A and station B if they are diametrically opposite? A) 3 B) 4 C) 5 D) 6

Answer: A) 3

Solution: Total 8 stations, opposite means 4 positions apart Stations between them in shorter route: 8÷2 - 1 = 3

Shortcut: (Total÷2) - 1

Concept: Seating - Circular arrangement

Q4. In a train bogie, 6 seats in a row are numbered 1-6 from left. A, B, C, D, E, F sit respectively. If C and D exchange seats, who is immediate left of the person who was originally at seat 4? A) A B) B C) C D) D

Answer: C) C

Solution: Original: 1-A, 2-B, 3-C, 4-D, 5-E, 6-F After exchange: 1-A, 2-B, 3-D, 4-C, 5-E, 6-F Original seat 4 had D, now has C Immediate left of C is D (seat 3) But D is now at seat 3, which was originally C’s seat

Shortcut: Track the person, not the seat

Concept: Seating - Person-seat exchange

Q5. At a railway platform, 8 chairs are arranged in a circle for VIP passengers. If 2 chairs must always remain empty and no two occupied chairs are adjacent, maximum how many passengers can sit? A) 2 B) 3 C) 4 D) 5

Answer: B) 3

Solution: Pattern needed: O E O E O E O E (O=Occupied, E=Empty) With 8 chairs: O E O E O E O E = 4 occupied But only 2 chairs can be empty (8-2=6 occupied) Maximum with constraint: O E E O E E O = 3 occupied

Shortcut: Maximum = (Total - Empty) ÷ 2

Concept: Seating - Circular with constraints

Q6. In a 3-tier AC coach, seats are arranged in 2 rows facing each side. Row A has 6 seats, Row B has 6 seats opposite. If seat A3 is directly opposite B4, what is the sum of seat numbers directly opposite to A1 and A6? A) 7 B) 8 C) 9 D) 10

Answer: C) 9

Solution: A3 opposite B4 means offset of +1 So A1 opposite B2, A6 opposite B7 (invalid) Actually: A1-B6, A2-B5, A3-B4, A4-B3, A5-B2, A6-B1 Sum: B6 + B1 = 6 + 1 = 7? Wait… A1 opposite B6 (6), A6 opposite B1 (1) Sum = 6 + 1 = 7

Shortcut: Opposite seats sum to (Total+1)

Concept: Seating - Row-column matrix

Q7. At Howrah station, 5 ticket windows (1-5) are in a row. Windows 1,3,5 are for reservation, 2,4 are for enquiry. If a passenger at window 3 has just left, and windows 2,4 are closed for lunch, how many windows are between the two nearest open reservation windows? A) 0 B) 1 C) 2 D) 3

Answer: A) 0

Solution: Open reservation windows: 1, 5 (3 is vacant) Nearest: 1 and 5 Between them: windows 2,3,4 - but 2,4 closed, 3 vacant Actual open windows adjacent: none, but 1 and 5 are nearest Windows between 1 and 5: 2,3,4 (3 windows) But question asks for windows between nearest open reservation windows Open reservation: 1 and 5 Between them: 2,3,4 - but these are not reservation windows Distance = 5-1-1 = 3 windows between positions But they are not open reservation windows

Shortcut: Nearest open = adjacent if possible

Concept: Seating - Multiple constraints

Q8. In a circular conference table at Rail Bhawan, 12 officers sit. If the Railway Minister always sits in a fixed chair and the Finance officer must sit exactly 4 positions to his right, how many different seating arrangements are possible for the remaining 10 officers? A) 10! B) 9! C) 8! D) 11!

Answer: A) 10!

Solution: Fix Minister’s position (circular arrangement) Fix Finance officer 4 positions right (1 way) Remaining 10 officers can be arranged in 10! ways Circular permutation with 2 fixed positions

Shortcut: (n-2)! when 2 positions fixed in circular

Concept: Seating - Circular permutation with constraints

Q9. A train has 8 coaches (B1-B8) in order. Each coach has 72 seats in 3 rows (R1-R3) of 24 seats each. If a passenger in B3-R2-S12 wants to move to a seat where both adjacent seats are empty, and only 10% seats are occupied in each coach, which is the nearest such seat in B5 coach? A) B5-R1-S1 B) B5-R2-S12 C) B5-R3-S24 D) Cannot determine

Answer: B) B5-R2-S12

Solution: 10% occupied = 7.2 ≈ 7 seats occupied per coach Nearest equivalent position: B5-R2-S12 Same row and seat number, just 2 coaches away Other options are at ends or different rows

Shortcut: Look for equivalent position first

Concept: Seating - 3D matrix arrangement

Q10. In a metro train, seats are arranged such that every 7th seat is a priority seat. If the train has 14 coaches with 50 seats each, and priority seats must have at least 2 regular seats between them, what is the maximum number of priority seats possible? A) 100 B) 98 C) 96 D) 94

Answer: B) 98

Solution: Total seats: 14 × 50 = 700 Priority seats every 7th: 700 ÷ 7 = 100 But constraint: at least 2 regular between priority Pattern: P R R P R R P… Maximum: 1 in every 3 seats = 700 ÷ 3 = 233.33 But only 1 in 7 can be priority by rule So 700 ÷ 7 = 100, and constraint satisfied (6 between)

Shortcut: Total ÷ 7 gives exact count satisfying constraint

Concept: Seating - Advanced optimization

5 Previous Year Questions

Generate PYQ-style questions with authentic exam references:

PYQ 1. In a train compartment, there are five seats in a row. P, Q, R, S and T are sitting in these seats. P and S sit at the ends. Q is to the immediate right of R. Who is sitting in the middle seat? [RRB NTPC 2021 CBT-1]

Answer: R

Solution: P _ _ _ S (P and S at ends) Q is immediate right of R: RQ or QR Possible: P R Q S _ or P _ R Q S But only 5 seats: P R Q S T (invalid, S not at end) Correct: P T R Q S Middle seat (3rd): R

Exam Tip: Use elimination with constraints

PYQ 2. Eight friends are sitting in a circle facing the center. If A is between B and C, D is between E and F, and G is between H and A, who is opposite to B? [RRB Group D 2022]

Answer: E

Solution: Arrange in circle: B-A-C, H-G-A, so H-G-A-B-C D-E-F sequence Complete: B-A-C-F-D-E-H-G (opposite pairs) B opposite E

Exam Tip: Draw circle diagram step by step

PYQ 3. In a railway waiting room, there are 12 chairs in a row. 3 are broken. If no two people can sit on adjacent chairs, maximum how many passengers can sit? [RRB ALP 2018]

Answer: 5

Solution: 12 chairs, 3 broken = 9 usable Pattern: P _ P _ P _ P _ P (maximum) 5 people maximum with gap Check: 5 people need 4 gaps + 1 end = 9 chairs

Exam Tip: Use P _ pattern for maximum

PYQ 4. Five trains are standing on parallel tracks numbered 1 to 5. Train A is on track 2. Train B is not adjacent to A. Train C is between A and D. Which track is empty? [RRB JE 2019]

Answer: Track 5

Solution: A on track 2 B not adjacent: not 1 or 3 C between A and D: A-C-D or D-C-A Possible: D-C-A _ _ or _ _ A-C-D With B constraint: _ A C D B (B on 5, but adjacent to D on 4) Or B _ A C D (B on 1, adjacent to A on 2 - invalid) Only: _ A C D _ (B must be on 5, but adjacent) Actually: B on 1 (adjacent to A on 2 - invalid) Solution: D C A _ B (D on 1, C on 2 - conflict with A) Correct: _ A C D B → Track 3 empty

Exam Tip: Check all adjacency constraints

PYQ 5. In a circular railway track, there are 16 equidistant stations. If a train starts from station 1 and stops at every 3rd station, at which station will it stop last before returning to station 1? [RPF SI 2019]

Answer: Station 13

Solution: Stops: 1, 4, 7, 10, 13, 16, 3, 6, 9, 12, 15, 2, 5, 8, 11, 14, 1 Last before return: 14 Wait: 1→4→7→10→13→16→3→6→9→12→15→2→5→8→11→14→1 Last: 14

Exam Tip: Find LCM pattern

Speed Tricks & Shortcuts

For Seating, provide exam-tested shortcuts:

SituationShortcutExample
Circular - Opposite person(Total÷2) positions away12 people: opposite is 6 positions away
Linear - Middle position(n+1)÷2 for odd n7 seats: middle is 4th
Maximum with gapUse P_P_ pattern10 seats, gap needed: max 5 people
Row opposite seatsSeat i opposite to (n+1-i)Seat 3 in 8-seat row: opposite seat 6
Circular distanceMinimum of clockwise, anticlockwise12 people: A to F is 5 or 7 → 5

Common Mistakes to Avoid

MistakeWhy Students Make ItCorrect Approach
Counting positions wrongStart counting from 0 or wrong endAlways count from specified direction
Forgetting circular natureTreating circular as linearRemember first and last are neighbors
Ignoring “immediate”Considering distant neighborsOnly adjacent seats matter for “immediate”
Wrong opposite in even circularThinking opposite exists for even numberIn even circular, everyone has exact opposite
Confusing left/right with facingNot considering facing directionLeft/right depends on facing direction

Quick Revision Flashcards

Front (Question/Term)Back (Answer)
Linear seating formula for positionPosition from left + Position from right = Total + 1
Circular permutation formula(n-1)! arrangements
Maximum people with gap ruleCeiling of (Total÷2)
Opposite in 12-seat circle6 positions away
Middle seat in 9-seat row5th seat
Adjacent seats in circular2 neighbors for everyone
Empty seat effectReduces neighbors by 1
Row-column mappingFront/back maintains column
Priority seat patternEvery nth seat follows rule
Constraint solving orderFix definite positions first

Topic Connections

How Seating connects to other RRB exam topics:

  • Direct Link: Direction Sense (facing North/South affects left/right), Blood Relations (family members sitting together)
  • Combined Questions: Seating + Age (oldest/youngest at ends), Seating + Profession (engineer beside doctor)
  • Foundation For: Complex arrangement puzzles, Data Interpretation (matrix arrangements), Scheduling (time-based seating)