Seven people, A, B, C, D, E, F and G, are sitting in a straight row, facing north. Only 2 people sit to the left of E. G is an immediate neighbour of E. B sits to the immediate right of F. Only 3 people sit between G and F. A sits to the immediate left of D. Who sits at the extreme left end of the row?
C
Understanding the Seating Arrangement Puzzle
This question is a classic seating arrangement puzzle where we are given a set of conditions about the positions of seven people (A, B, C, D, E, F, G) sitting in a straight row, all facing North. Facing North means that the left and right directions in the arrangement correspond to our left and right.
We need to use the given clues to determine the exact position of each person in the row and then identify the person sitting at the extreme left end.
Analyzing the Clues to Build the Seating Arrangement
Let's break down each clue and see how it helps us build the arrangement of the seven people in the straight row.
There are 7 positions in the row, let's number them from left to right: 1 2 3 4 5 6 7.
- Clue 1: Only 2 people sit to the left of E.
If only two people are to E's left, E must be in the 3rd position from the left end.
Current arrangement: \_ \_ E \_ \_ \_ \_
Positions: 1 2 3 4 5 6 7 - Clue 2: G is an immediate neighbour of E.
E is at position 3. G can be either at position 2 (immediate left of E) or position 4 (immediate right of E).
Case 1: G is at position 2. Arrangement so far: G E \_ \_ \_ \_ \_ (Positions 1 2 3 4 5 6 7)
Case 2: G is at position 4. Arrangement so far: \_ \_ E G \_ \_ \_ \_ (Positions 1 2 3 4 5 6 7) - Clue 3: B sits to the immediate right of F.
This means F and B are sitting together in that order (F followed by B) like a block 'FB'. - Clue 4: Only 3 people sit between G and F.
Let's test this clue with our two cases for G's position.
Consider Case 1 (G at position 2): G is at 2. If there are 3 people between G and F, F must be at position $2 + 3 + 1 = 6$ (adding 3 for the people in between and 1 for F's position relative to G).
Arrangement for Case 1 now: G E \_ \_ \_ F \_ (Positions 1 2 3 4 5 6 7)
Let's verify: People at positions 3, 4, and 5 are between G (at 2) and F (at 6). Yes, there are 3 people.
Consider Case 2 (G at position 4): G is at 4. If there are 3 people between G and F, F must be at position $4 + 3 + 1 = 8$. However, there are only 7 positions in the row. So, F cannot be at position 8. This means Case 2 is impossible.
Therefore, G must be at position 2, and F must be at position 6.
Our arrangement is now: \_ G E \_ \_ F \_ (Positions 1 2 3 4 5 6 7) - Applying Clue 3 again: B sits to the immediate right of F.
F is at position 6. B must be immediately to its right, which is position 7.
Arrangement: \_ G E \_ \_ F B (Positions 1 2 3 4 5 6 7) - Clue 5: A sits to the immediate left of D.
This means A and D sit together as 'AD'.
The positions filled so far are 2(G), 3(E), 6(F), and 7(B).
The remaining people are A, C, and D. The remaining positions are 1, 4, and 5.
We need to place A, C, and D in positions 1, 4, and 5 such that A is immediately left of D ('AD').
Looking at the available positions (1, 4, 5), the only way to place 'AD' together is in positions 4 and 5 (A at 4, D at 5). Position 1 cannot accommodate 'AD' as there is no position 0 for A.
So, A is at position 4 and D is at position 5.
Arrangement: \_ G E A D F B (Positions 1 2 3 4 5 6 7)
Completing the Seating Arrangement
We have placed G, E, A, D, F, and B. The only remaining person is C. The only remaining position is position 1.
Therefore, C must sit at position 1.
The final arrangement from left to right is:
| Position | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|
| Person | C | G | E | A | D | F | B |
Identifying the Person at the Extreme Left End
The extreme left end of the row is position 1.
Based on our final arrangement, the person sitting at position 1 is C.
Conclusion
By carefully analyzing each clue and systematically building the arrangement, we determined that C sits at the extreme left end of the straight row.
Revision Table: Seating Arrangement Clues & Deductions
| Clue | Deduction | Partial Arrangement / State |
|---|---|---|
| 7 people, straight row, facing North. | 7 positions: 1 2 3 4 5 6 7 | \_ \_ \_ \_ \_ \_ \_ |
| Only 2 people sit to the left of E. | E is at position 3. | \_ \_ E \_ \_ \_ \_ |
| G is an immediate neighbour of E. | G is at position 2 or 4. | Case 1: G E ... Case 2: ... E G ... |
| Only 3 people sit between G and F. | Combined with G's position and 7 seats, F must be at position 6 (if G is at 2). Case 2 (G at 4) is ruled out as it requires > 7 seats. | \_ G E \_ \_ F \_ |
| B sits to the immediate right of F. | F is at 6, so B is at 7. | \_ G E \_ \_ F B |
| A sits to the immediate left of D. | Remaining people (A, C, D) must fill remaining spots (1, 4, 5). 'AD' must be together. Only possible at 4 and 5. A at 4, D at 5. | \_ G E A D F B |
| Remaining person is C. | Remaining position is 1. C is at 1. | C G E A D F B |
Additional Information on Linear Seating Arrangements
Linear seating arrangement puzzles are common in logical reasoning sections of exams. They involve arranging people or objects in a straight line based on given conditions.
- Key Elements: Number of people/objects, direction they are facing (North, South, or mixed), and relative positioning clues (left/right of someone, between two people, at the ends, number of people between).
- Facing North vs. South: If everyone faces North, your left is their left, and your right is their right. If everyone faces South, their left is your right, and their right is your left. Mixed directions require careful attention to each person's facing direction.
- Solving Strategy:
- Draw a diagram representing the positions (blanks or numbered spots).
- Start with the most definite clues (e.g., someone sitting at an end, a specific number of people to one side of someone).
- Combine related clues (like 'FB' block).
- Consider possible cases if a clue presents options (like G being on either side of E) and rule out cases that contradict other clues or the total number of positions.
- Fill in positions as you deduce them.
- Use remaining people and positions to fit the last clues.
- Always re-read all clues to verify the final arrangement.
Important Questions from Linear Arrangement
Eight friends, A, B, C, D, E, F, G and H, are sitting in two lines of four persons each. Both the lines are facing each other. A is facing D. E is to the immediate left of G. H is to the immediate right of B. C is facing G. F is facing H. B is to the immediate right of the person who is facing G. D is to the immediate left of F. Which four persons are sitting in the same line?
Nine employees, K, L, M, N, O, P, Q, R and S, are sitting in the office in a straight line, all facing the east. O is third to the right of M. K is third to the left of P. Q is between P and S. N is fourth to the right of M. P is to the immediate right of N. R is fourth to the left of O. Which of the following statements is NOT correct?
Eight north-facing restaurants named P, Q, R, S, T, U, V and W are located in a straight line. S is second to the left of T. W is third to the left of P. T is between P and V. S is third to the left of V. W is to the immediate right of U. R is third to the right of P. Who is sitting fourth to the right of S?
Anamika, Gopal, Nischal, Vanmayi, Shresta and Sripad are sitting in a straight line facing the north. Nischal is to the immediate left of Gopal. Shresta is between Anamika and Sripad. Sripad is at the second place from the right end. Four persons are sitting between Nischal and Vanmayi. If Gopal and Sripad interchange their positions, then who will be sitting between Vanmayi and Shresta?
A question is given, followed by two statements numbered (I) and (II). You have to decide whether the data provided in the statements is sufficient to answer the question. Read both the statements and select the appropriate answer.
Question: How many people are standing in the row where all people are facing north?
Statements:
(I) A is fourth from the left end; M is second to the right of A; and R is second from the left end.
(II) M is fourth from the right end; only two people Stand between M and B.
