Seating arrangement and puzzles for SSC CGL

Seating arrangements and puzzles are where many candidates lose time in SSC reasoning. A single question can take two or three minutes if you approach it by trial and error. With a method — draw the frame, fix the definite clues, branch where needed — most SSC-level arrangements take under a minute and a half. And because several questions often share one arrangement, the time invested pays off more than once.

Left and right

Picture yourself standing at the bottom of a round table, facing the centre. Your right hand points to the right of the page; moving that way around the table from where you stand is anticlockwise. That is why, facing the centre, right = anticlockwise.

The method

1. Draw the frame — a row of places or a circle with the right number of seats.
2. Place definite clues first — "A sits at the extreme left", "B sits opposite C".
3. Link relative clues — "D sits second to the right of A".
4. Branch when a clue allows two positions — draw both cases side by side.
5. Eliminate cases that break any clue.
6. Answer all questions from the final arrangement.

A linear arrangement

Worked example: Six people — P, Q, R, S, T and U — sit in a row facing north.

• Q sits at an extreme end.
• R sits second to the right of Q.
• T sits immediately to the left of R.
• U sits at the other extreme end.
• S does not sit next to U.

Facing north, right is towards the right of the page. Q must be at the left end (otherwise "second to the right" is impossible), so Q is in seat 1 and R in seat 3. T, immediately to the left of R, is in seat 2. U is in seat 6. S is not next to U, so S cannot be in seat 5: S is in seat 4 and P in seat 5.

Final order (left to right): Q, T, R, S, P, U.

• Who sits between R and P? S.
• Who is second to the left of U? S.

A circular arrangement

Worked example: Six friends — A, B, C, D, E and F — sit around a round table facing the centre.

• A sits opposite D.
• B sits immediately to the right of A.
• C sits second to the right of D.
• F sits immediately to the left of D.
• E does not sit next to A.

Number the seats 1 to 6 clockwise. Place A in seat 1, so D (opposite) is in seat 4. Facing the centre, right is anticlockwise, so B is in seat 6. Second to the right of D (anticlockwise from 4) is seat 2, so C is in seat 2. Left is clockwise, so F is in seat 5. Only seat 3 remains for E — and seat 3 is not next to A, as the clue requires.

Final arrangement (clockwise): A, C, E, D, F, B.

• Who sits opposite C? F.
• Who sits immediately to the right of E? Anticlockwise from seat 3 is seat 2: C.

Other puzzle types

Worked example (comparison): Among five friends, P is taller than Q but shorter than R. S is taller than R. T is the shortest. Who is the tallest?
Chain: S > R > P > Q > T. S is the tallest.

Time management

• Read all the questions attached to a puzzle before you start.
• If the arrangement isn't clear within 90 seconds, move on and return in Round 2.

Practice

1. Five people A, B, C, D and E sit in a row facing north. A is at the left end. C is immediately right of A. E is at the right end. B is not next to C. Who is in the middle?
2. P is heavier than Q, Q is heavier than R, and S is lighter than R. Who is the lightest?
3. In a building with five floors (1 at the bottom), X lives above Y but below Z. W lives on floor 1. V lives on floor 5. Z lives on floor 4. On which floor does X live?

Answers: 1. D (order A, C, D, B, E). 2. S. 3. Floor 3 (Y must be on floor 2).