J, K, L, M and N are sitting on a bench. J is the immediate neighbour of K, M is the immediate neighbour of N, and J is not sitting with L who sits on the right end of the bench. J sits to the right of M and N. M sits to the right of N. In which position is J sitting?
Third from the left
Solving the Seating Arrangement Logic Puzzle
This question is a classic linear seating arrangement puzzle. We need to determine the exact position of each person on the bench based on the given clues and then identify J's position.
Let's list the constraints given:
- There are 5 people: J, K, L, M, and N.
- J is the immediate neighbour of K (implies J and K are side-by-side).
- M is the immediate neighbour of N (implies M and N are side-by-side).
- J is not sitting with L (implies J and L are not immediate neighbours).
- L sits on the right end of the bench.
- J sits to the right of M and N.
- M sits to the right of N (implies N is to the left of M).
Let's represent the 5 positions on the bench from left to right:
1 2 3 4 5
Using the constraints, we can deduce the arrangement:
- L sits on the right end. This means L is at position 5.
\_ \_ \_ \_ L - M sits to the right of N, and J sits to the right of M and N. This establishes the relative order N ... M ... J from left to right.
- Combining N ... M ... J with L at position 5, the sequence N, M, and J must occupy positions to the left of L. Since there are only 4 positions left (1, 2, 3, 4), and they must be in the order N, M, J, the most compact way to fit them consecutively and respect the relative order N...M...J is N-M-J.
- Let's try placing the N-M-J sequence directly to the left of L. This would look like N M J \_ L.
N M J \_ L - We have one person left, K. The empty spot is position 4. So, K must be at position 4.
N M J K L - Now let's check if this arrangement N-M-J-K-L satisfies all the initial conditions:
- J is the immediate neighbour of K: Yes, J is at position 3 and K at position 4.
- M is the immediate neighbour of N: Yes, M is at position 2 and N at position 1.
- J is not sitting with L: Yes, J is at position 3 and L at position 5. They are not adjacent.
- L sits on the right end: Yes, L is at position 5.
- J sits to the right of M and N: Yes, J is at position 3, M is at 2, N is at 1. 3 is to the right of 2 and 1.
- M sits to the right of N: Yes, M is at position 2, N is at position 1. 2 is to the right of 1.
All conditions are satisfied by the arrangement N-M-J-K-L.
The seating arrangement from left to right is:
| Position | Person |
|---|---|
| 1st from left | N |
| 2nd from left | M |
| 3rd from left | J |
| 4th from left | K |
| 5th from left (Right End) | L |
The question asks for the position of J.
Based on the arrangement N-M-J-K-L, J is at position 3 from the left.
Let's also check the position from the right. From the right, L is 1st, K is 2nd, J is 3rd. So J is also 3rd from the right.
Looking at the options provided, "Third from the left" is an option.
Revision Table for Seating Arrangements
| Constraint Type | Meaning | How to Use |
|---|---|---|
| Immediate Neighbour | Two people are next to each other. | Place them as a block (e.g., JK or KJ). |
| Sits to the Right/Left Of | Relative positioning, not necessarily immediate. | Establish the order (e.g., N...M means N is left of M). |
| Sits on the End | Person is at position 1 (left) or 5 (right). | Fix a person's position at one end. |
| Not Sitting With | Usually means not immediate neighbours. | Avoid placing them adjacent in the final arrangement. |
Additional Information on Logic Puzzles
Logic puzzles like this seating arrangement problem are common in aptitude tests. They require careful reading and step-by-step deduction. It's useful to list down all the conditions and use a visual representation (like drawing the bench positions) to help place people and check constraints. Start with the most fixed conditions (like someone sitting at an end) and then use the relative positioning and neighbour conditions to fill in the gaps.
When solving such puzzles, it's important to:
- Read all clues carefully before starting.
- Identify absolute positions first (like ends).
- Group individuals based on immediate neighbour clues.
- Use relative position clues (left/right of) to build sequences.
- Systematically eliminate possibilities if needed (though in this case, a single consistent arrangement was found).
- Verify the final arrangement against all original clues.
Important Questions from Linear Arrangement
- Five people (A, B, C, D and E) are sitting in a straight line. They all are facing towards the north. B is sitting immediately between C and E. A is sitting third to the left of E. C is sitting second to the right of D. Who is sitting at the extreme left end of line?
- Six people A, B, C, D, E and F are sitting in a straight line. All are facing towards North.
B is seated third from the extreme right end of the line.
Only two people are seated between B and E.
C is sitting second from the right of B.
F is an immediate neighbour of B and C.
A is sitting to the immediate right of D.
How many people are seated between D and F? - Seven people A, B, C, D, E, F and G are sitting in a row, facing the north. Only three people sit to the left of D. B sits third to the left of D. F sits to the right of A but left of D. E sits to the right of C but left of G. How many people sit to the right of F?
- Seven people, I, J, K, L, M, N and O, are sitting in a row, facing north. Only three people sit to the left of M. Only I sits to the right of O. Only three people sit between O and N. J sits at some place to the left of K but at some place to the right of L. How many people sit between L and K?
- Seven people A, B, C, D, E, F and G are sitting in a row, facing north. Only two people sit between D and C. Only G sits to the right of E. Only one person sits between C and E. A sits at some place to the right of F but at some place to the left of B. How many people sit to the right of A?
